Green lb unit) Newsletter DENVER botanic gardens, inc.

Copyright 1975

NUMBER 75-1 JANUARY 1975 TELEPHONE 297-2547

NEW YEAR S GREETINGS FROM THE DIRECTOR

The year 1974 is now history — and we will all admit it
was quite a year! More importantly, the year 1975 is now a
reality, stretching out ahead of us, providing for us the raw
materials from which we can fashion our plans, our hopes,
and our dreams, not only for the lives of each of us, but for
our Botanic Gardens as well.

At this time I should like to extend both my congratu¬
lations and my deep gratitude to all of you in the “Denver
Botanic Gardens Family” whose hard work and diligence
made possible our most productive year since the Gardens
officially came into being with its incorporation in February
1951. It is a pleasure to report to you that we should all
feel very proud of our various successes in 1974. I suggest
that we consider our inability to reach some of our goals
(always the other side of the coin of success) not as a cause
for discouragement, but rather as an additional incentive for
accomplishment in 1975.

To each of you individually who compose our greater
Botanic Gardens Family — Mayor McNichols and the City
Council, Manager Ciancio and his staff, members of the
Botanic Gardens Board of Trustees, the Gardens Staff, to
our wonderful host of volunteers and to our Members and
Friends, the Botanic Gardens extends its wishes that 1975
will be a most rewarding year with a full measure of good
health, sufficient prosperity, and much joy in accomplish¬
ment. With your continued cooperation, and hard work on
the part of us all, we are certain to make 1975 still another
great year for the Denver Botanic Gardens — a year of
dedicated service to the people of Denver and the State of
Colorado.

William G. Gambill, Jr.

What do your gardeners do in the winter?

Well, for one thing six staff members took four days last
month to plow gardens for the Mayor’s Senior Citizen
Vegetable Garden Project.

Last year a pilot project involved some 500 senior
citizens in gardening. Many more expressed a desire to
participate in the coming year so we were happy to do our
part. Six areas from 13th and High to 32nd and Elm were
deep plowed and at one garden, the site of an old dump,
truckloads of trash were hauled away also.

The Denver Commission on Aging was in charge of
coordinating the project. Three prime objectives listed were:
to help participating seniors stretch their food budget; to
provide a project that would have social as well as economic
benefits; to bring together senior citizens and young people
in a meaningful, cooperative venture.

And something to remember as the growing season
nears, these gardens could use extra flowering plants to
beautify the borders. If anyone has some herbaceous plants
to contribute or can help in any other way, please call
Nancy Good at 377-8767 or 297-3205.

The Botany Club meeting on January 17 at 7:30 p.m.
will provide a rare visual treat for flower lovers. Bill
Eisenlohr has spent over 10 years photographing flowers; in
his “two screen” presentations he will show over 200 species
of Colorado natives. Appropriate background music with a
taped narration ties the slide show together. All welcome.

Another scheduled club meeting, that of Around the
Seasons, promises to provide a fascinating speaker on a most
timely subject. Mo Siegel, the 24 year old president of
“Celestial Seasonings” will speak on the “Growing Interest in
the Use of Herbs” on January 16 at 11 a.m. (Perhaps some
of our readers saw the article on Mr. Siegel and his firm in
the Denver Post last month.) Four years ago Mo began
picking, drying and selling herbs around Boulder. Today with
60 employees the Company has national distribution. Guests
welcome.

Something New in the Conservatory

A large flat topped tree aloe, Aloe bainesii has recently
been purchased from Bruggenthies. It has been planted at
the west end of the conservatory near the waterfall (no one
will have difficulty finding it for these are the largest of the
aloe and can grow up to 60 feet). After a photographer from
the News came, guides reported that for two weeks children
asked to see “the tree who’s picture was in the paper.”

* * * *

Membership at the Denver Botanic Gardens now stands
at 2597. Forty-four new members were signed up at the
Christmas Sale because of the effort of the Development and
Public Relations Committee and the Hostess/Information
Desk Volunteers.

Good News!

The following people have completed the fall Guides
Training class and will soon be leading tours in the
Conservatory:

Maggie Apodaca
Lisa Bardwell
James Black
Lavinia E. Black
Robina Bland
Jim Borland
Mildred H. Earhart
Mary Eiseman
Marcia K. Falk
Judith M. Gerhardt
Shirley

Victoria E. Kennedy
Joan Krueger
Susan Marshall
Carolyn McLaughlin
Judy Moore
Jennis Rhoades
Pamela Rodeffer
Mary Rollins
Pat Steavenson
Juanita Swigeart
Timmons

Welcome to you all.

A new class will start soon. Why not plan to join? This
will begin on January 8 and continue until April 2 from 1 to
3 PM. The cost is $25.00 to be refunded if a student guides
for a total of 40 hours.

Other classes include Plant Communities and Ecosystems
on Tuesdays from January 7 to February 25, 1 to 3 PM in
Classroom B. Dr. Denham will discuss the fundamentals of
ecology including the bioenergetics of floral ecology and
energy conservation and transfer. The cost for this academic
class is $20.00 for members of Denver Botanic Gardens and
$25.00 for non-members.

Also would you please search your collection of
Scientific American magazines for the September 1970 issue
entitled Biosphere V. 223, No. 3? Copies are needed for Dr.
Denham’s class. If you have that issue and would not mind
our borrowing it for the month, please call Solange Huggins
at 297-2547, Ext. 24.

Home Landscaping is designed to assist home owners in
planning and maintaining a desirable outdoor living area.
Such subjects as site analysis, design, plant materials, plant¬
ing, lawn installation and care, pruning and maintenance of
the finished product will be covered in illustrated lectures. In
this class it might be particularly valuable to have both
husband and wife attend so they may jointly plan their
property. (Did you realize in all the classes a participating
Denver Botanic Gardens member may bring one member of
the family for $3.00 more?)

Larry Watson of Western Evergreen, Inc., noted for its
fine collection of native plants and A1 Rollinger who wrote
Low Maintenance Gardens for the Sunset Garden Books will
be the instructors. The course is scheduled for January 9 to
February 27 from 7:30 to 10 p.m. in classroom C., $10.00
for members and $15.00 for non-members.

Those of you who bought dried material at the
Christmas Sale (and those who didn’t but wish you had)
should sign up for Dried Flower Arrangement. Avalonne
Kosanke who designed such striking decorations for the
Christmas tree will teach this from January 22 to February
12, 10 to noon. The cost is $10.00 for members, $15.00 for
non-members (plus $1.50 per session for materials). Working
with ordinary field, woods, roadside and garden materials,
plus some unusual items, Mrs. Kosanke will take each
student as rapidly as possible toward modern and advanced
designing.

Finally on January 25, at 9 a.m. in Horticulture Hall,
the Hi-Hopes Study Club will sponsor their African violet
workshop. This is an opportunity to really ask questions
about anything that interests you about this most popular of
house plants. There will be a fifty cent charge payable at the
door. And when you come on the 25th, look at the beauti¬
ful display in the library. Our thanks go to Hi-Hopes Study
club members who are faithful in sharing their plants with
us. Hi-Hopes has a membership of 16 and has been display¬
ing plants here for four years.

People who missed out on the House Plants class may
wish to join a course offered by the Community College on
this same subject. It will meet every Wednesday evening in
February at 1005 York Street. The cost is $15.00.

For further information please call Sara Collier,
266-1881.

Memorial gifts have been received in memory of Mrs.
William Jacobs.

Notes from the Library ....

A reminder to all that the book drop at the gate house
may be used for the return of books when desired.

Because of the great popularity of house plant books,
this particular category classified SB 419, will no longer be
renewable.

Finally, start saving your books and magazines for the
book sale in the Spring. We will pick up donated material if
you call Solange Huggins at 297-2547 ext. 24 for an
appointment.

* * * *

“Spring Loves Scandinavia” is the title of the free film
to be shown on January 11 at 1:30, Classroom C. This will
continue our series of lovely colored films of beautiful areas
and flowers of the world.

Mr. William Rice, Mrs. Paul Fullerton, Jr., Miss Grace Barger,
Dr. William Gambill, Mr. David Blades

Gift to the Greenhouse Collection

A lovely collection of orchids has been given to the
Denver Botanic Gardens in honor of Mr. B. Walter Slagle.
Mr. Slagle, former President of the American Orchid Society,
was a charter member and first president of the Denver
Orchid Society. Some of the better specimens include:
Laeliocattleya Walter Slagle (named in his honor),
Phalaenopsis Grace Palm, and Laeliocattleya Cassiopea.

Members will be sorry to learn of the death of George
T. Fukuma. Mr. Fukuma was a very active member of
both of the Bonsai clubs. He frequently taught Begin¬
ning and Advanced Bonsai classes at the Denver
Botanic Gardens. He was a gentle patient teacher and
well liked and respected by all his students. We will
miss him.

Again this year the Denver Museum of Natural History
is offering cruises to the Baja California area. There are two
trips scheduled:

1. Islands of the Pacific and San Ignacio Lagoon:
March 1—9, 1975. Two days and nights in San Diego are
included as well as a six-day cruise sailing from San Diego.
We will stop at several unusual desert islands to observe
elephant seals, sea lions, and bird life; then visit San Ignacio
Lagoon where we will take time to make close-up observa¬
tions of gray whales.

2. Gulf of California — Midriff Islands: April 19—27,
1975. This trip includes two days and nights in San Diego
plus a six-day cruise sailing out of San Felipe, Mexico. We
will see nesting boobies, terns, pelicans and gulls as well as
intertidal life and magnificent cardon cactus forests on
several desert islands. We will observe the pod of fin whales
that makes its permanent home in the Gulf. Fishing is
excellent so bring your gear.

For further information please contact the Denver
Museum of Natural History.

Janus was the Roman God of Beginnings who
looked both forward and back so in this month named in his
honor, perhaps it would be appropriate to think back on the
striking displays of plants used in the Lobby Court area last
year. In January many varied plant forms were seen by the
visitors as Euphorbias from the greenhouse collection were
on display; a pre-spring planting of red tulips, blue cinerarias
and many colored primroses were next followed by the
Easter lilies and yellow calceolarias; next came more
blossoms with white and pink geraniums; a change of scene
was provided by the Ikebana club who built a Japanese
garden in the area. This featured rocks, trees, goldfish in the
pool and even a “deer-chaser.” (Remember a bamboo rod
which filled with water and dropped against a rock with a
loud clunk.) Gloxinias were then used and probably the
most popular display this year, that of tuberous begonias
followed. The cavalcade continued with bromeliads, chrysan¬
themums and finally the year ended on a most colorful note
with red, white and pink poinsettias.

Looking ahead the tentative display schedule is:

January-February

March

March-April

April

May

June

July-August

September-October

November

December

Cactus, Succulents
Orchid display
Easter display
Spring bulbs
Plant Sale display
Gloxinias
Tuberous begonias
Bromeliads
Chrysanthemums
Christmas display

Please remember that the Board of Trustees has estab¬
lished a Lobby Court Memorial Fund. This is used so the most
handsome displays possible will greet our many visitors to
the Education Building.

ATTENTION GUIDES — Past, Present or Future!

The Guides meeting on January 22 will be a slide show
on the tropical and sub-tropical plants of the Conservatory,
illustrating their growth and use. This has been a long term
project of the guides and will be presented complete with
narration. The time is 1 p.m. in the main room of the
Denver Botanic Gardens House.

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The House is in need of a brass floor lamp for the
dining room. Mr. Higbee donated one which is most appro¬
priate and now we would like to have a similar one for the
other side of the room. We would be glad to pick it up so if
anyone has a lamp that might be suitable, please call
297-2547.

The Sixteenth Annual Colorado Garden and Home Show
will be held in Currigan Hall from January 31 to February 9,
1975. The theme is “A Touch of Spring” and a parade of
patios will be featured. The hours are Saturdays noon to 10
p.m., Sundays noon to 6 p.m.; Wednesday matinee 2 to 10
p.m. and the remaining weekdays 6 to 10 p.m.

The Denver Botanic Gardens will have the membership
tree on display so all plan to come down and visit us.

Green Thumb Newsletter is published monthly by Denver Botanic Gardens,
Inc., 909 York Street, Denver, Colorado 80206. The Newsletter is included as a
benefit of membership in the Denver Botanic Gardens, regular membership dues
being $10.00 a year. Items for publication are welcome. The deadline for copy
to the editor is 2:00 p.m. on the 10th of each month preceding publication.
Editor — Margaret Sikes, 297-2547, Ext. 23.

GreeJjTbUmb Jfetyslctfcr DENVER BOTANIC GARDENS, INC.

Copyright 1975

NUMBER 75-2 FEBRUARY 1975 TELEPHONE 297-2547

FEBRUARY CLASSES

Just for fun! Children may be interested in learning the
technique of drying flowers in Flower Preservation. This
class on February 8 and 15 will meet at 9 a.m. in Classroom
B. Students are requested to sign up ahead of time so the
proper amount of material may be provided. The cost is
$3.00 and the class is limited to 15 children ages 12 to 15,
please.

A change of pace will take place with a group Tour of
the Art Museum. The museum’s collection of 19th and 20th
Century paintings will be discussed. After the tour, plan on
remaining for a dutch-treat lunch. The group is limited to 20
so get your name in now, set up car pools with your friends
and meet in the foyer of the Museum, 100 W. 14th Avenue
Parkway, at 10:30 a.m. on February 19. No charge but plan
on making a $1.00 donation to the Art Museum, please.

Another free class will be provided on Saturday,
February 22, in How to Make Your Own Herbarium. This
will be helpful to those joining the field trips later or for
those who may wish to collect on their own.

Remember Richard Jefferies who said: “The first
conscious thought about wild flowers was to find out their
names — the first conscious pleasure — and then I began to
see so many that I had not previously noticed. Once you
wish to identify them, there is nothing escapes . . . .”

Dr. Zeiner will teach this class at 9 a.m. in the
Herbarium.

Finally, if you were quick enough to sign up for House
Plants for the Amateur don’t forget the first date is
February 6. (It may sound silly to mention but each class
has some students who forget the opening date!)

If you could not enroll in the House Plant course
perhaps you should consider buying the Brooklyn Botanic
Garden Handbook on House Plants. No one is more aware of
the many pitfalls and problems of growing house plants than
the experts at the Brooklyn Botanic Garden. For many years
they have conducted popular courses in raising all kinds of
plants indoors and have answered thousands of questions
posed by windowsill gardeners. Based on this experience of
sensing the needs of indoor growers, twenty-three experts
have written an informative paperback book which contains
answers to the questions most often asked of the Gardens’
Plant Information Service.

To aid in tracking down all the plants mentioned in the
handbook, there is a directory to dozens of mail-order
nurseries and also a very helpful list of further readings.
Among the 58 illustrations are many showing attractive ways
to decorate with house plants.

The “House Plant Primer” is available for $1.50 at the
Denver Botanic Gardens Gift Shop.

Lecture and Demonstration

“How to Grow House Plants” will be the title of an
illustrated lecture to be given on February 12 at 8 p.m. in
Horticulture Hall.

Mr. Ralph L. Snodsmith, Executive Director of the
Queens Botanical Garden in Flushing, N.Y. will stress
interior decoration and selection of suitable house plants
along with cultural requirements in his talk. Mr. Snodsmith,
a native of Illinois, with degrees from the University of
Illinois in Floriculture and Ornamental Horticulture, has
served in his present position for five years. He has written
for such publications as The New York Times - Garden
Section, and has conducted a weekly radio show aimed at
aiding and educating the consumer horticulturist.

This lecture is limited to members and their guests only.
Please present your membership card at the door. Members
of the Associates will act as hostesses.

Good News and Bad News!

Ruth Christie who has done such fine work here (she is
the female part of the Dr. Green troika and has arranged the
stunning displays around the Lobby Court) was recently
married. She will be living in Grand Junction. We shall miss
her but our best wishes go with her!

Free Film!

Another award winning film from the American Horti¬
cultural Society will be shown on February 8 at 1:30 p.m.
in Classroom C. “Beauty for All Seasons” shows the glories
ot Kingwood Center, Mansfield, Ohio, throughout the year!
All Welcome.

And speaking of the American Horticultural Society,
have you thought of the benefits of membership?

The American Horticulturist .... a bimonthly mag¬
azine, now in its fifty-second year - the only publication in
the horticultural field offering original articles by both
amateur and professional gardeners. Read about new plant
introductions, culture, breeding .... plant diseases and pest
control .... techniques of weed control .... notes on air
pollution damage to plants and trees .... garden topics and
insights into the new field of indoor gardening .... environ¬
mental horticulture .... landscaping tips and ideas .... how
gardeners can attack visual pollution .... book reviews
how-to-do-it material .... and much more 'in color,
illustrated.

Seed Distribution Service .... provides members with a
free choice of hundreds of seeds from unusual and rare
specimens of plants and trees from all over the world. It is
one of the Society’s most popular services and a boon to the
gardener who is looking for something different to grow.

Gardener’s Information Service .... gives you thorough
answers to your tough and technical questions in sensible
down-to-earth language. An information resource for
gardeners in all parts of the country.

News and Views .... the Society’s award-winning
bimonthly newsletter .... keeps members informed of the
Society’s activities. It’s also full of new gardening ideas,
landscaping inspirations .... environmental tips .... timely
developments in the world of gardening and horticulture
. . . . where to buy what .... when and how to plant ....
hundreds of valuable items of information .... and your
own questions answered in special columns by experts who
write in spritely and informative language.

Information on the American Horticultural Society is
available in the Helen Fowler Library or write:

The American Horticultural Society
Mt. Vernon, Virginia 22121

Also another project of the Society is a nationwide
horticultural certification program awarding the “American
Diploma in Horticulture,” to applicants who meet prescribed
standards, demonstrating art and skill in horticultural
practices. The program is not conceived to compete with
degree training in schools and colleges where the emphasis is
more academic, with less stress on performance and practical
gardening skills.

Requirements are a minimum of 24 months working
experience, recommendations from at least three recognized
horticulturists, and a brief but comprehensive outline of a
project that shows an above-average horticultural
achievement.

Qualified candidates undergo five hours of examinations
emphasizing performance other than education. The
examinations will be given at regional centers and admin¬
istered by professional horticulturists and botanists. Deadline
for applications is March 1st.

Forms may be obtained from the American Horti¬
cultural Society, Mt. Vernon, Virginia 22121 or call Dr. J.
R. Feucht, 355-8306, for further information.

And lastly, your children may be interested to learn
about the National Junior Horticultural Association which is
affiliated with the American Horticultural Society. Their
stated objectives are:

1. To promote and sponsor an educational program of
projects and activities for youth which relate to a better
understanding of horticulture. The program is designed both
for those who wish to make horticulture a hobby and for
those who wish to make it their profession.

2. To acquaint youth with the many and varied career
opportunities, both vocational and professional, available in
the horticultural industry.

They hope to reach these goals by projects and activities
such as Environmental Beautification. Participation in this
includes a wide variety of project categories: planting flowers
and ornamentals, controlling erosion, developing and rehabili¬
tating recreation areas, improving roadsides, and generally
beautifying urban and rural “eyesores.”

The Production and Marketing Contest has to do with
the culture of a wide variety of horticultural crops
(vegetables, fruits, flowers, or ornamentals) for home use or
for commercial sale through such outlets as roadside stands,
wholesale markets, retail stores, florists’ shops, and nurseries.
Also included is growing and selling vegetables and fruits
under contract to canning or other food processing firms.

Evaluation of the project is based on a written report on
organization, cost, cultural practices and procedures involved
in tire sale or use of the product.

Projects dealing with plant nutrition, the relation of
light, temperature or water to plant response, the effect of
various chemicals on growth, and reproduction or in
extending the storage period for vegetables, fruits and
flowers are just a few examples of interesting studies under
the Experimental Horticulture Project.

Other contests and projects are available for students
under 21 years of age.

The Denver Botanic Gardens will have a class on
Identification of Woody Ornamentals, starting March 1,
which it is hoped will be of interest to NJHA members.
Look for it in the Spring List of Classes soon to be mailed.
But in the meantime, if you are interested in learning more
about NJHA, please call Ms. Peggy O’Neill at 935-5724.

Does the name of Liberty Hyde Bailey strike a
responsive chord? This man for whom the most prestigious
award in American Horticulture is named has been called
“the most outstanding and productive individual in the
entire history of horticulture and gardening in the U.S.”

L. H. Bailey played an overwhelming part in shaping the
direction of agriculture and gardening in the country. He
served as a professor of horticulture at Michigan and later at
Cornell where he was chosen director and first dean of the
new College of Agriculture.

He was a prodigious writer: His Standard Cyclopedia of
Horticulture is often the first source turned to for help on
questions. Hortus II and Bailey’s Manual of Cultivated Plants
are also still much used by today’s gardeners.

All of the above leads to the fact that the American
Horticultural Society gave the Liberty Hyde Bailey Medal to
F. L. Steve O’Rourke this past year. Professor O’Rourke is
well known to many of our members for he taught at
Colorado State University for years. He also gave lectures in
the Denver Botanic Gardens series. Our congratulations to
him!

DENVER BOTANIC GARDENS
CALENDAR OF EVENTS
FEBRUARY, 1975

FEBRUARY

1)

9:30 a.m.

Botanic Gardens House - Main Room

Gloxinia Gesneriad Growers

3)

11:00 a.m.

Botanic Gardens House —

Main— Dining & Kitchen

Rocky Mountain Belles

3)*

7:00 p.m.

Education Building — Lecture Room “B”

Floral Design Workshop — Mr. Lee Ashley

4)*

10:00 a.m.

Education Building — Herbarium

Herbarium Committee Meeting

4)*

1:00 p.m.

Education Building — Lecture Room “B”

Ecology — Dr. M. Denham

4)*

1:00 p.m.

Botanic Gardens House — Dining Room

Editorial Committee Meeting

4)

7:30 p.m.

Botanic Gardens House — Dining Room

Denver Audubon Society (Wildlife Workshop)

5)*

8:00 a.m.

Botanic Gardens House — Main Room

Equipment Class — Mr. Mike Clark

5)*

10:00 a.m.

Education Building — Lecture Room “B”

Dried Flower Arrangement — Mrs. Robert Kosanke

5)*

1 :00 p.m.

Education Building - Lecture Room “A”

Tropical Plants of the Conservatory —

Mrs. P. Hayward

5)*

7:00 p.m.

Education Building — Lecture Room “A”

“House Plants” — Mr. Richard Hannigan

5)*

7:00 p.m.

Education Building — Lecture Room “B”

Floral Design Workshop — Mr. Lee Ashley

6)*

8:00 a.m.

Botanic Gardens House — Main Room

Equipment Class — Mr. Mike Clark

6)*

10:00 a.m.

Education Building — Lecture Room “B”

House Plants for the Amateur —

Mr. Richard Hannigan

6)*

6:30 p.m.

Education Building — Lecture Room “B”

General Botany — Dr. Hugh Wingate

6)*

7:30 p.m.

Education Building — Lecture Room “A”

Hobby Greenhouse Management —

Mr. Robert Briggs

6)*

7:30 p.m.

Education Building — Lecture Room “C”

Home Landscaping — Mr. A1 Rollinger &

Mr. Larry Watson

6)

7:30 p.m.

Education Building — Horticulture Hall

Colorado Open Space Council

6)

7:45 p.m.

Botanic Gardens House — Main Room

Denver Orchid Society

7)*

1 1 :00 a.m.

Botanic Gardens House —

Main— Dining & Kitchen

Civic Garden Club

7)*

7:00 p.m.

Education Building — Lecture Room “B”

“House Plants” — Mr. Dave Woodward

8)*

9:00 a.m.

Education Building — Lecture Room “B”

Flower Class for Children — Judy Weaver

8)

10:00 a.m.

Education Building — Lecture Room “A”

Colorado Organic Growers & Marketers Association

8)

1 : 30 p.m.

Education Building — Lecture Room “C”

♦ ♦♦♦♦♦

Film — “Kingwood Center”

♦ ♦ ♦

10)*

7:30 p.m.

Education Building — Lecture Room “B”

Floral Design Workshop — Mr. Lee Ashley

10)

7:30 p.m.

Education Building — Horticulture Hall

Colorado Mycological Society

11)*

9:30 a.m.

Education Building — Lecture Room “B”

Civic Garden Club — Division “C”

11)*

1:00 p.m.

Education Building — Lecture Room “B”

Ecology — Dr. M. Denham

11)*

4:00 p.m.

Botanic Gardens House — Dining Room

Executive Committee Meeting

12)*

9:30 a.m.

Botanic Gardens House — Main Room

D.B.G. Guild

12)*

10:00 a.m.

Education Building — Lecture Room “B”

Dried Flower Arrangement — Mrs. Robert Kosanke

12)*

1:00 p.m.

Education Building — Lecture Room “A”

Tropical Plants of the Conservatory —

Mrs. P. Hayward

12)*

7:00 p.m.

Education Building — Lecture Room “A”

“House Plants” — Mr. Richard Hannigan

12)*

7:00 p.m.

Education Building — Lecture Room “B”

Floral Design Workshop - Mr. Lee Ashley

12)*

7:30 p.m.

Botanic Gardens House — Dining Room

Landscape Industry Council

12)

8:00 p.m.

Education Building — Horticulture Hall

“How to Grow House Plants” —

Dr. Ralph L. Snodsmith (Executive Director -
Queens Botanical Garden, Flushing, N.Y.)

13)*

10:00 a.m.

Education Building — Lecture Room “B”

House Plants for the Amateur —

Mr. Richard Hannigan

13)*

6:30 p.m.

Education Building — Lecture Room “B”

General Botany — Dr. Hugh Wingate

13)

7:00 p.m.

Education Building — Lecture Room “A”

Sierra Club — Conservation Committee

13)

7:00 p.m.

Education Building — Horticulture Hall

Sierra Club — (Ski program)

13)*

7:30 p.m.

Education Building — Lecture Room “C”

Home Landscaping — Mr. A1 Rollinger &

Mr. Larry Watson

13)

8:00 p.m.

Botanic Gardens House —

Main— Dining & Kitchen

Denver Rose Society

CALENDAR OF EVENTS FOR FEBRUARY (Continued)

14)*

7:00 p.m.

Education Building — Lecture Room “B”

14)

7:30 p.m.

Botanic Gardens House —

15)*

9:00 a.m.

Main— Dining & Kitchen

Education Building — Lecture Room “B”

16)

1:30 p.m.

Botanic Gardens House —

17)*

7:00 p.m.

Main-Dining & Kitchen

♦ ♦♦♦♦♦

Education Building — Lecture Room “B”

18)

9:00 a.m.

Education Building — Horticulture Hall

18)*

1 :00 p.m.

Education Building — Lecture Room “B”

18)

7:30 p.m.

Education Building — Horticulture Hall

18)

7:30 p.m.

Education Building — Lecture Room “B”

19)*

1 :00 p.m.

Education Building — Lecture Room “A”

19)*

7:00 p.m.

Education Building — Lecture Room “A”

19)*

7:00 p.m.

Education Building — Lecture Room “B”

19)

7:30 p.m.

Education Building — Lecture Room “C”

20)*

10:00 a.m.

Education Building — Lecture Room “B”

20)*

10:00 a.m.

Botanic Gardens House — Main Room

20)*

6:30 p.m.

Education Building — Lecture Room “B”

20)

7:00 p.m.

Education Building — Horticulture Hall

20)*

7:30 p.m.

Education Building — Lecture Room “C”

20)

7:30 p.m.

Education Building — Lecture Room “A”

21)*

7:00 p.m.

Education Building — Lecture Room “B”

21)

7:30 p.m.

Education Building — Lecture Room “C”

22)

9:00 a.m.

Education Building — Herbarium

24)*

7:00 p.m.

♦ ♦*♦♦♦

Education Building - Lecture Room “B”

25)*

1:00 p.m.

Education Building — Lecture Room “B”

25)

7:30 p.m.

Education Building — Lecture Room “C”

26)*

1:00 p.m.

Education Building — Lecture Room “A”

26)*

7:00 p.m.

Education Building — Lecture Room “A”

26)*

7:00 p.m.

Education Building — Lecture Room “B”

26)

7:30 p.m.

Education Building — Lecture Room “C”

26)

7:30 p.m.

Botanic Gardens House — Dining Room

27)*

10:00 a.m.

Education Building — Lecture Room “B”

27)*

6:30 p.m.

Education Building — Lecture Room “B”

27)*

7:30 p.m.

Education Building — Lecture Room “C”

27)

7:30 p.m.

Botanic Gardens House —

28)*

10:00 a.m.

Main— Dining & Kitchen

Education Building — Horticulture Hall

28)*

7:00 p.m.

Education Building — Lecture Room “B”

MARCH

1)

9:30 a.m.

♦ ♦♦♦♦♦

Education Building - Lecture Room “A”

1)

9:30 a.m.

Botanic Gardens House — Main Room

“House Plants” — Mr. Dave Woodward
Denver Dahlia Society

Flower Class for Children — Judy Weaver
Hemerocallis Society

♦ ♦, ♦

Floral Design Workshop — Mr. Lee Ashley
“Improving Your Professional Image & Pruning
Practices” — Dr. J. Feucht & Ken Hostetle
Ecology — Dr. M. Denham
Sierra Club

Denver Jr. Bonsai Club

Tropical Plants of the Conservatory —

Mrs. P. Hayward

“House Plants” — Mr. Richard Hannigan
Floral Design Workshop — Mr. Lee Ashley
Colorado Mycological Society — Workshop - “lv
Mr. George Grimes
House Plants for the Amateur —

Mr. Richard Hannigan
Around the Seasons
General Botany — Dr. Hugh Wingate
Sierra Club

Home Landscaping — Mr. A1 Rollinger &

Mr. Larry Watson
Organic Gardening Club of Denver
“House Plants” — Mr. Dave Woodward
Denver Botany Club
“How to Make Your Own Herbarium”

Dr. Helen Zeiner
♦ ♦ ♦

Floral Design Workshop — Mr. Lee Ashley
Ecology — Dr. M. Denham
Gladiolus Society

Tropical Plants of the Conservatory —

Mrs. P. Hayward

“House Plants” — Mr. Richard Hannigan
Floral Design Workshop — Mr. Lee Ashley
Colorado Mycological Society — Workshop - “1”
Mr. George Grimes
Colorado Open Space Council —

(Wilderness Workshop)

House Plants for the Amateur —

Mr. Richard Hannigan
General Botany — Dr. Hugh Wingate
Home Landscaping — Mr. A1 Rollinger &

Mr. Larry Watson
Men’s Garden Club of Denver

Ikebana International

“House Plants” — Mr. Dave Woodward

♦ ♦ ♦

National Jr. Horticulture Class
Gloxinia Gesneriad Growers

*Members or enrollees only.

Ruth Nelson Talks February 20

Ruth Ashton Nelson, botanist and author, will describe
her activities in preparing her latest book, Plants of Zion
National Park, when she speaks informally to members of
Around the Seasons Club, February 20 at 11 a.m. at Botanic
Gardens House. Visitors are welcome.

“Posies to Print! or Making a Plant Book involved
collecting, recording data, identifying and preparing
herbarium specimens for the Zion National Park collection at
Springdale, Utah. During the past four years Mrs. Nelson has
lived for several weeks at different times in park quarters
and most of that time was spent in the field. She did most
of the identifying at her home near Estes Park. Currently her
book is with the book designer and the publisher, Zion
Natural History Association, is hopeful it will be available
for the 1975 season.

Mrs. Nelson’s previous books are Plants of Rocky
Mountain National Park, first published in 1933 by the U.S.
Park Service, revised in 1953, and updated and republished
in 1970 by the Rocky Mountain Nature Association; and
Handbook of Rocky Mountain Plants, also published in
1970, in which she described plants of the Rocky Mountains
from Northern Arizona and New Mexico to Canada. Each of
her publications was prepared for the amateur botanist as
well as for the classroom.

Mrs. Nelson, as a child, spent many summers in the high
Colorado Rockies where she developed an intense interest in
wildflowers. At Mt. Holyoke College she majored in botany
and writing. For several years she worked for the govern¬
ment at Rocky Mountain National Park and also toward her
Master’s degree in botany at now Colorado State University.
She is the wife of the late Aven Nelson, one of the great
Rocky Mountain botanists, professor of botany and curator
of the herbarium at the University of Wyoming. Together
they spent many summers collecting plants and working in
the herbarium. She has travelled and photographed wild¬
flowers throughout Europe and spent many months studying
wildflowers and setting up a private herbarium in Greece.

Something to Anticipate . . .

Last February the first of the spring bulbs bloomed! We
can all hope to see flowers again soon so watch in the
sunken garden area around the Golden-rain trees. The first of
all last year was a yellow Crocus chrysanthus ‘E. P. Bowles.’
Also other early plants were Iris danfordiae and Eranthis
hyemalis, both with yellow flowers. Iris histriodes var.
‘Major’ is blue and also watch for Anemone blanda ‘Rosea'
light red and C. chrysanthus ‘Snowbunting’ a beautiful
white.

Plants Alive, the lovely indoor plants and greenhouse
journal, has an idea for the dull days of winter that some of
our readers might wish to try. Why not make a crocus ball!
First, take sphagnum moss and shape it into a ball. Then
place crocus bulbs all over the moss; tie in place with green
string and cover with more moss. Then trim the moss but
leave a long string to hang by. Soak the ball well and hang
in a cool, dark place. When sprouting starts, moisten more
often. When buds appear bring the ball into the light ‘and
finally enjoy the blooms.

Seedling Trees Available

Landowners who plan to purchase seedling trees for
spring planting from the Colorado State Forest Service may
pick up order blanks now. Blanks are available from local
offices of the CSFS, CSU Extension Service and Soil
Conservation Service.

Landowners wishing to buy seedlings must agree to
some conditions: the planting site must be used for con¬
servation planting and trees cannot be sold as living
specimens at a later date.

And another project of the Colorado State Forest
Service is a new publication, “Tree Talk!” which is available
in the Library. The purpose of the pamphlet is to establish a
communication link with municipal foresters. However,
many of the articles are of general interest. For example, did
you know that crews for the CSFS surveyed the City and
County of Denver last summer for Dutch elm disease? As of
August 30, Denver had a population of 34,109 American
elms. Of these 4,917 are symptomatic of DED. Intensive
sanitation and an increase in the use of methoxychlor
protective sprays have definitely helped to slow DED in the
metropolitan area.

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As reported in the last newsletter, we have a fine new
group of guides who are currently hard at work providing
toifts for the many visitors in the conservatory. As spring
nea^s we always have . more requests than can be granted so
the Guides Committee has completed two projects to use the
volunteers’ time in a more efficient manner.

A large shadow box has been built which shows tropical
fruits like the ear pod and the kukui nut. This handsome
box is displayed on its own easel, both made by Harold
Bergkamp, husband of one of the guides. Members of the
committee provided the plant material, did the background
art work and the informative cards.

Another project which is planned for use when we have
more visitors than can be toured at one time, is a slide show
of the tropical plants in the conservatory. Over 70 slides
were provided by Peg Hayward and Ruth Van Etten. A
written narrative to go with the slides makes a fine educa¬
tional presentation. The Guides are also working on an
informative note book which is soon to be completed.

Too, an inventory of plants has been compiled by Larry
Latta and Beverly Nilsen. This work of several months’
duration will be particularly helpful to the guides for now
we know exactly what plants are present in the
conservatory.

Finally, a recommendation to all guides or to anyone
else interested in the program — please see The American
Association of Botanical Gardens and Arboreta, July, 1974.
The emphasis of the issue is on youth and four articles deal
with educational programs from Longwood to Berkeley.

Reminder

Although we and the printers try hard, we do know that
not all members receive the newsletter by the first of each
month. For this reason the first week of the next month is
always shown on the Calendar of Events.

Care to Share?

Black and white glossy prints of wildflowers, native trees
and shrubs, as well as cultivated species, will be gratefully
accepted for the photo file at the Denver Botanic Gardens.
Pictures are needed as illustrations in the Gardens’
publications. Makers will be acknowledged whenever their
pictures are used. Please contact Margaret Sikes, 297-2547
ext 23 if you have any jewels you are willing to share or
bring them to Helen McCloskey at the Botanic Gardens
House.

The National Parks and Conservation Magazine reports
in its November issue that preservation of endangered species
of plants is finally receiving long overdue attention.

The Endangered Species Act of 1973 directed the
Smithsonian Institution to review species of plants that are
now or may become endangered or threatened and methods
of conserving such species.

Accordingly in cooperation with the other federal
agencies and all 50 states, the Smithsonian had assembled by
August 1974 a preliminary list of species of plants that are
endangered, threatened or extinct. Heretofore not enough
was known about the status of plants in order to plan an
effective conservation program for them. The Smithsonian’s
first phase effort will provide the information with regard to
the higher plants. The second phase will include identifying
endangered nonvascular plants.

“Sweetheart of the Rockies” is the theme of the Rocky
Potters African Violet Club’s annual Plant Show and Sale.
The event is scheduled for February 8th and will be held at
the Holiday Inn, 800 28th Street in Boulder. The club
anticipates a wide variety of plants to be displayed. Every¬
thing from leaves to blooming plants will be for sale. For
further information contact Sharon McElhoe, 421-0641
evenings.

Green Thumb Newsletter is published monthly by Denver Botanic Gardens,
Inc., 909 York Street, Denver, Colorado 80206. The Newsletter is included as a
benefit of membership in the Denver Botanic Gardens, regular membership dues
being $10.00 a year. Items for publication are welcome. The deadline for copy
to the editor is 2:00 p.m. on the 10th of each month preceding publication.
Editor — Margaret Sikes, 297-2547, Ext. 23.

Grecmhumb Newsletter DENVER BOTANIC GARDENS, IN

DENVER BOTANIC 1 ’ s Copyright 1974

NUMBER 75-5

HELEN

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vTrk St. Denvfar> CotoMAY 1975

TELEPHONE 297-2547

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^ 1 1975

GARDENING TIPS FOR MAY

In 1972 this column started with the following
sentence: “After an early start, an abrupt slowdown, and a
new start, spring seems to be on its way”. This sentence
could be repeated this year in light of the rather mild
conditions during March, then the below zero temperatures
on April 2, followed by another warm-up. Anyone who has
lived in Colorado long enough knows that one should take
advantage of the mild periods between cold snaps to get the
garden ready. I hope that you did this year so that you do
not have to spend a lot of time now getting the soil ready
for planting.

May is planting month and now would be the time to
plant out any new perennials you plan to add to the garden;
and by the middle of the month, most all annuals can be
put out with the exception of the very tender types, such as
tomatoes and eggplant. For these I would wait until
Memorial Day, or at least until night time temperatures are
over 50 degrees. Setting them out too soon tends to hold
them back, and fruit-set usually does not occur until the
fifty-degree night time average has been reached.

For good quality bedding plants, as well as trees and
shrubs, you should shop early. In fact, for trees and shmbs,
shopping should be well completed by now unless you
intend to purchase container stock only.

When buying plants, look for quality first and price
second. For example, petunias and other bedding plants
should be dark green in color, have stout stems and short
internodes (leaves close together). Preferably, they should be
branching at the base which is an indication that they have
been pinched back and were grown in uncrowded conditions
in a fertile soil. Bedding plants that are tall and stringy will
usually be very slow to establish and will require additional
pinching back at planting time. This will usually set them
back several days to weeks.

I also prefer to purchase bedding plants not in flower. It
is better to pinch off the flowers at planting time because
root growth is more important and when plants are in flower
there is a tendency to have slower root growth.

When putting your bedding plants out, particularly those
in peat pots, or in similar “plantable” containers, be sure to
break the peat pots in several places to allow root penetra¬
tion, and plant them so that the rim of the pot is below soil
level. If the rim is exposed to the air, it will act as a wick,
drawing moisture from the root zone.

Plants that are in plastic containers or similar “non-
plantable” types will usually have a dense ball of roots when
they are taken from the container. At planting time, take a
sharp knife and score the sides of the root ball in several
places about %” deep. This will promote rooting out into
the new soil and prevent the tendency for the root system
to stay within the ball.

Vegetable gardens are the “in” thing and in fact, many
are trying to plant vegetables instead of garden flowers. I
would like to suggest a companion garden. Many vegetables
are attractive in themselves and could be considered com¬

panions to the perennials and annuals. Leaf lettuce comes in
various textures and colors and makes an excellent edging
plant. The red-leafed forms and the crisped varieties add
interest to a garden and would thus serve a double purpose;
form an edging around the garden and provide salads for
your table. The rhubarb variety of chard with its red stems
is also an effective vegetable. The same could be said for
beets. They would incidentally, tolerate a considerable
amount of shade. There is also no reason why onions and
chives could not be used as a low edging in the front of the
flower garden. Whether any of the latter actually repels
insects is quite debatable. I have seen no real evidence that
they do, and in fact, chives have their own insect pests and
thrips on onions could be a problem with other garden
flowers.

Speaking of insects that will soon be upon us in droves,
before you grab the sprayer, be sure spraying is warranted.
Frequently we apply pesticides unnecessarily because of the
habit of spraying at the sight of the first bug. Find out what
the insects are first. Decide whether they are really doing
damage, then apply appropriate controls as necessary. For
those wishing to experiment with biological methods, keep
in mind that you should not expect miracles and that
parasites and predatory insects in the artificial environment
of our cities, rarely, if ever, give satisfactory results. Such
biological methods are way more effective in large areas or
on single crops such as alfalfa. At least one should not
expect perfect control. After all, if a beneficial insect
destroys its own food supply, it will have to die or move
into someone else’s yard.

It is hard to predict what the water situation will be this
year. I personally feel that we are going to see limitations on
lawn watering but this does not mean you cannot still have
a lawn. Many of us are so accustomed to turning on a
sprinkler on an every other day basis that we have gotten
into the habit of wasting water. It is possible to keep a lawn
green even through the hot, dry months by applying water
properly and not wasting the water. To do this, one must
know what type of soil is being watered. Heavy clays cannot
be watered rapidly since very little moves into the soil and
more will tend to run off. Watering slowly but deeply is a
more effective use of water; and the less frequent the better.
Deep and infrequent watering will tend to promote deeper
rooting of the turf. Keeping the lawn cut to a height of no
less than one. and three-fourths inches will also help to
conserve moisture and be better for the grass as well. Rather
than watering on an every other day schedule, try to water
according to the needs of the grass. A good indicator of a
need for water is when the grass begins to turn a bluish cast,
or when foot prints remain in the turf. In any case, there is
no single recommendation that can be given for watering.
Each yard and each soil, and the various types of exposure
are variables that must be taken into consideration.

Dr. J. R. Feucht

* * * *

In the first three months of 1975, the Gardens played
host to 8,411 more visitors than in 1974.

Members will be saddened to learn of the death of Dr.
A. C. Hildreth. Dr. Hildreth served as Director of the
Cheyenne Horticulture Field Station for 14 years prior
to assuming the Directorship of the Denver Botanic
Gardens in July 1959. He became Director Emeritus in
October 1966.

A lengthy catalogue of accomplishments could be
written for this distinguished horticulturist, but all of
the honors pale before the character of the man himself.

His great knowledge grounded in his scientific
research was generously shared in person and in his
writings. Always the information was imparted with a
twinkling eye and spiced with dry humor and sly wit.
Goodbye, Dr. Hildreth. We won’t forget you!

Memorial funds for Dr. Hildreth have been designated
for the Children’s Garden, a project dear to his heart.

PLANT SALE

The Denver Botanic Gardens Annual Plant Sale will be
held Friday and Saturday, May 9 and 10 from 9:30 a.m. to
5:30 p.m. in and around the Boettcher Memorial Center,
1005 York Street.

During this event a wide selection of locally grown
plants, suitable for a variety of growing conditions, will be
offered: annuals, perennials, berries, herbs, vegetables, trees,
shrubs, rock garden and ground cover plants, African violets,
house plants.

Each year volunteers who specialize in the culture of
their favorites sell thousands of plants and give information
and suggestions for planting.

This year’s accent will be on growing your own flavorful
fruits and vegetables, a pursuit which home gardeners have
found assures tastier, more nutritious food and affords
healthful outdoor exercise. At the Vegetable Booth will be
found plants of pascal celery, eggplant, broccoli, cabbage,
cauliflower, peppers, cucumbers and cantaloupe, plus many
varieties of tomatoes. The Berry Basket has the same fine
selection of plants as last year, but has increased quantities
of all items so no one will go away empty handed. One
addition to look for is ‘sequoia’ strawberry, a large foliage,
one crop plant that makes a lush ground cover.

Flowers at the Annuals Booth will range from Ageratum
to Zinnia with many letters in between. Some plants to
watch for include ‘Redskin’ dahlias, ‘Blue Skies’ petunias and
open faced snapdragons like ‘Madame Butterfly’ and ‘Little
Darling’.

Perennials are a main stay of all gardens. If you would
like to do some research prior to the sale, look at Arnoldia,
November, December 1974 and January, February 1975.
These publications of the Arnold Arboretum are beautifully

illustrated with line drawings and pictures and are full of
information on varieties and culture of perennials. They are
available in the Helen Fowler Library.

While you are there be sure to visit the Book Nook
where library volunteers will be selling used books and
magazines. Proceeds will be used to expand the Library
collection.

AND LAST CHANCE If you have been intending to
donate books for this year’s Library used book sale there are
only a few days! left. Contributions may be left at the
Gatehouse or at the Library, marked for the sale. The dates
of the sale coincide with those of the Plant Sale — May 9th
and 10th.

This year the House Plant booth will offer six different
carnivorous plants, plus a miniature plastic greenhouse kit
containing carnivorous plants, moss and growing instructions.
Lithops, ficus, orchids, cacti, bromeliads, large specimen
plants, the ever popular “string-of-beads”, exotic ferns,
hibiscus, bougainvillea and rare terrarium plants will also be
available.

New among the native wild flowers and ground covers
featured at the Rock Garden Booth will be a red flowered
cinquefoil, Potentilla thurberi. Actually a native of New
Mexico and Arizona, the plant, which has been grown
especially for this sale, is hardy at 8,500 elevation and
blooms from July into September and October.

Two columbines, the alpine, Aquilegia saximontana,
with dainty white cup and blue saucer on 3 inch plants, and
the blunt-spurred red columbine, A. elegantula, on plants less
than a foot high will be prized by dedicated rock gardeners.
Of course, Colorado columbine will be available also.

Other popular natives include western shooting star,
saxifrage, blue-eyed grass, as well as pink plumes, pussytoes
and a few Easter daisies. A red penstemon, Penstemon
pinifolius, resembling tiny junipers growing in a mat with
vermillion red spikes 6 to 8 inches tall when in bloom is an
excellent ground cover. Among cultivated plants will be
sunroses in various colors, coralbells, unusual sedums, named
varieties of hen and chicks plus various pinks, penstemons
and veronicas.

Many kinds of annual and perennial culinary herbs, plus
a variety of scented geraniums will interest all who visit the
Herb Booth. Aside from the old kitchen standbys like chives,
parsley, marjoram, thyme, basil and tarragon, look for lemon
balm, salad burnet, lovage, coriander and caraway. Dittany -
of-Crete and a decorative curry plant have proved to be
especially interesting in indoor and outdoor plantings.

Macrame hangers from elegant to plain-Jane practical
and hangers of wooden beads, seashells, and lucite chain can
be found at the Patio Show of the Gift Shop.

A wide selection of planters and cache pots in vibrant
color, subdued patterns and color in ceramic, glass and

basketry will be assembled for your choice.

Included will be cache pots in elegant porcelain, fanciful
animal and insect decorated planters and bonsai dishes in
basic design. Tools and “how-to” books for making ter¬
rariums are other items to be shown. For the unusual, try
one-of-a-kind handblown glass terrariums in unique design or
handcrafted stained glass originals by Gallus.

Items for the bird lover include birch bark teepees,
rustic houses of unpeeled bark, ceramic birdbaths, and
hummingbird feeders.

Other products offered will be copper fountains; wind-
chimes in bronze, colored glass, ceramic or bamboo; wrought
iron plant display racks; bamboo plant stands and baskets in
a wide selection of shapes, sizes and designs.

DENVER BOTANIC GARDENS

t

CALENDAR OF EVENTS

MAY

MAY, 1975

1)*

9:00 a.m.

Education Building — Horticulture Hall

Solar Energy Conference

1)*

7:30 p.m.

Education Building — Lecture Room “C”

Colorado Open Space Council — Board Meeting

1)

7:45 p.m.

Education Building — Horticulture Hall

Denver Orchid Society

2)*

9:00 a.m.

Education Building — Horticulture Hall

Solar Energy Conference

2)*

1 1:00 a.m.

Botanic Gardens House — Main -
Dining and Kitchen

Civic Garden Club

3)*

9:00 a.m.

Education Building — Lecture Room “B”

Bottle Gardens — Mr. R. Hannigan

3)

9:30 a.m.

Botanic Gardens House — Main Room

♦ ♦♦♦♦♦♦

Gloxinia Gesneriad Growers

♦ ♦ ♦ ♦

6)*

10:00 a.m.

Education Building — Herbarium

Herbarium Committee Meeting

6)*

3:30 p.m.

Education Building — Lecture Room “C”

Children’s Garden Meeting (Advanced)

6)

7:30 p.m.

Botanic Gardens House — Main Room

Denver Bonsai Club

6)

7:30 p.m.

Botanic Gardens House — Dining Room

Denver Audubon Society (Wildlife Workshop)

7)

7:30 p.m.

Botanic Gardens House — Main Room

Colorado Mycological Society

8)*

3:30 p.m.

Botanic Gardens House — Dining Room

Development & Public Relations Meeting

8)

8:00 p.m.

Botanic Gardens House — Main Room

Denver Rose Society

9)

9:30 a.m.

Education Building — Horticulture Hall
and Surrounding Area

ANNUAL PLANT SALE -

OPEN TO PUBLIC 9:30 a.m. - 5:30 p.m.

9)

7:30 p.m.

Botanic Gardens House — Main -
Dining and Kitchen

Denver Dahlia Society

10)

9:30 a.m.

Education Building — Horticulture Hall
and Surrounding Area

ANNUAL PLANT SALE -

OPEN TO PUBLIC 9:30 a.m. - 5:30 p.m.

10)

10:00 a.m.

Botanic Gardens House — Main Room

♦ ♦♦♦♦♦♦

Colorado Organic Grower’s & Marketer’s Association

♦ ♦ ♦ ♦

12)

7:30 p.m.

Education Building — Horticulture Hall

Colorado Mycological Society Meeting

12)

7:30 p.m.

Botanic Gardens House — Main Room

Sierra Club (Wildlife Workshop)

13)*

9:30 a.m.

Education Building — Lecture Room “B”

Civic Garden Club — Division “C”

13)*

4:00 p.m.

Botanic Gardens House — Dining Room

Executive Committee Meeting

14)

7:30 p.m.

Education Building — Lecture Room “A”

Colorado Mycological Society

14)*

7:30 p.m.

Botanic Gardens House — Dining Room

Landscape Industry Council

15)*

10:00 a.m.

Botanic Gardens House — Main Room

Around the Seasons Meeting

15)

7:30 p.m.

Education Building — Lecture Room “C”

Organic Gardening Club of Denver

16)

7:30 p.m.

Education Building — Herbarium

Denver Botany Club

17)

8:00 a.m.

Botanic Gardens House — Parking Lot

Field Trip to N.C.A.R. — Boulder - Limit 20
(8:00 a.m. at D.B.G. or 9:00 a.m. at

N.C.A.R. Parking Lot, Boulder)

17)

8:30 a.m.

Botanic Gardens House — Main Room

American Society of Landscape Architects

17)

9:30 a.m.

Education Building — Horticulture Hall

♦ ♦♦♦♦♦♦

Men’s Garden Club of Denver — Gardening Symposium
Board of Directors Meeting

Box Lunch

♦ ♦ ♦ ♦

19)*

2:00 p.m.

Education Building — Lecture Room “A”

Library Committee Meeting

20)

7:00 a.m. —
7:00 p.m.

Education Building — Horticulture Hall

ELECTION DAY

20)

7:00 p.m.

Botanic Gardens House — Main -
Dining and Kitchen

Rocky Mountain African Violet Council

20)

7:30 p.m.

Education Building — Horticulture Hall

Sierra Club

20)

7:30 p.m.

Education Building — Lecture Room “B”

Denver Bonsai Club

21)

9:00 a.m.

Botanic Gardens House — Parking Lot

PLANT LIFE'FIELD TRIP -
Dr. E. H. Brunquist

CALENDAR OF EVENTS FOR MAY (Continued)

I i

21)

7:30 p.m.

Education Building — Lecture Room “A”

Colorado Mycological Society

22)

7:30 p.m.

Education Building — Lecture Room “A”

.Capitol Hill United Neighborhood Meeting

22)

7:30 p.m.

Botanic Gardens House — Main -

Dining and Kitchen

Men’s Garden Club of Denver

23)*

10:00 a.m.

Education Building — Horticulture Hall

Ikebana International

1

24)*

7:00 a.m.

Botanic Gardens House - Parking Lot

Field Trip to Pawnee Grassland —

(7:00 a.m. at 909 York or 9:00 a.m. at Briggsdale)

Mr. Steve Cowgill, Instructor (Limit 20)

27)*

4:00 p.m.

Botanic Gardens House — Conference Room

Board of Trustees Meeting

27)

7:30 p.m.

Education Building — Lecture Room “C”

Gladiolus Society Meeting

28)

7:30 p.m.

Education Building — Lecture Room “C”

Colorado Open Space Council (Wilderness Workshop)

31)

8:30 a.m.

Botanic Gardens House — Main Room

American Society of Landscape Architects

31)

1:30 p.m.

Education Building — Horticulture Hall

Iris Society Show & Sale —

OPEN TO PUBLIC 1:30 to 5:00 p.m.

♦ ♦♦♦♦♦♦

♦

♦

♦

♦

JUNE

1)

9:00 a.m.

Education Building — Horticulture Hall

Iris Society Show & Sale

OPEN TO PUBLIC 9:00 a.m. - 5:00 p.m.

3)*

10:00 a.m.

Education Building — Herbarium

Herbarium Committee Meeting

3)*

1 :00 p.m.

Botanic Gardens House — Dining Room

Editorial Committee Meeting

3)

7:30 p.m.

Botanic Gardens House — Dining Room

Denver Audubon Society (Wildlife Workshop)

3)

7:30 p.m.

Education Building — Lecture Room “B”

Denver Bonsai Club

4)

9:00 a.m.

Education Building — Horticulture Hall

Colorado Water Color Exhibition Show
(Through June 19th)

5)*

7:30 p.m.

Education Building — Lecture Room “C”

Colorado Open Space Council — Board Meeting

5)

7:45 p.m.

Education Building — Horticulture Hall

Denver Orchid Society

6)

9:00 a.m.

Education Building — Horticulture Hall

LEADERSHIP DENVER

7)*

9:00 a.m.

Education Building — Lecture Room “B”

Rocky Mountain Belles —

(Judging Class, Instructor: Mrs. Emma Lahr)

8)*

9:00 a.m.

Education Building — Lecture Room “B”

Rocky Mountain Belles (Judging Exam)

♦ ♦♦♦♦♦♦♦♦♦♦

*For members or enrollees only.

For a Mother’s Day gift sure to please, make your
selection from the many garden and home oriented gifts
shown in the Gift Shop itself!

We are not having a film this month as usual, but will
have continuous showings all day, both days, in Classroom A
during the Plant Sale. Some of the titles are: “An Educated
Green Thumb,” “The World of Roses”, and “Foliage Plants
for Interiors”.

Last year we sold 104 memberships at Plant Sale, so
steer your friends toward the Membership Booth and let’s
top that record!

Finally, you can help the Gardens grow by donating
your surplus plants. Any type of growing plant, including
herbs, shrubs, trees, rock garden or ground cover, miniature
iris .... any growing plant can be sold and will be most
appreciated.

Your donations may be brought through the Gaylord
Street entrance beginning Monday, May 5. After entering the
gate, turn left and place your donation on the wood chip
surface. To help preserve your plants, they can be placed in
cans, cottage cheese or milk cartons. Covering freshly dug
plants with plastic, after sprinkling, helps retain moisture.
Please identify and label your plants when possible.

Besides your plants, we can use you! Willing workers are
needed in all areas. Call 297-2547, leave your name and area
where you’d like to help and we will call you. It’s fun and
you’re needed.

REMINDER - THE GARDENS WILL BE CLOSED AT
NOON ON THURSDAY, MAY 8, SO WE CAN GET
READY FOR THE BIG DAYS TO FOLLOW. SEE YOU
ON MAY 9 AND 10!

If you don’t help, you may have to stand in line at
Plant Sale, if so, cheer your spirits by admiring the over
4,500 tulips planted near the display beds along York Street.
The Netherlands Flower-Bulb Institute donated many beauti¬
ful varieties which were planted last October. Some to watch
for include Darwin type: ‘Aristocrat’, ‘Sweet Harmony’ and
‘Queen of Night’. Darwin hybrids: ‘Oxford’, ‘Jewel of
Spring’, and ‘Gudoshnik’. Lily flowered types: ‘West Point’,
‘Red Shine’, ‘Mariette’ and ‘White Triumphator’ and Mid
season: ‘Sulphur Glory’ and ‘First Lady’.

Congratulations to:

Lew Hammer of Lew Hammer, Inc., Denver, has been
elected president of the Associated Landscape Contractors of
America. Hammer’s firm, the largest landscape contractor in
Colorado, won an environmental award for its landscaping of
Denver Mariott Hotel.

MAY CLASSES

Dr. Brunquist will lead a Field Trip on May 21. Please
meet at 9 a.m. at 909 York Street. Bring lunch and share
expenses with the driver. Since our participants seem to be
better taxonomists than mathematicians, the mileage is
figured thusly: 6<t per mile divided by all in the car,
including driver. Example: 60 miles @ 6<t per mile $3.60;
occupants of car, driver plus 3 riders = 4; $3.60 divided by 4
= 90$ per person for the trip.

The above is especially important on trips like that on
May 24 to Pawnee Grasslands since it is a long drive. Meet at
7 a.m. at 909 York Street or at 9 a.m. at Crow Valley Park
in Briggsdale, take Hwy. 14 out of Ault. Limit 20 and
please, no sign-ups before May 12. When you do sign up,
please indicate if you can drive.

Those of you who are going on this trip might enjoy
looking at An Interpretive Resource Analysis of Pawnee
Buttes, Colorado. This was written by R. J. Badaracco as
partial requirement for his Ph.D. degree from Colorado State
University and is available in the Helen Fowler Library.

If you really wish to study this fascinating area, a pro¬
posed National Monument Site, the Denver Audubon Society
and the University of Northern Colorado will sponsor a
Grasslands Institute there June 16 to 22.

For more information, please contact Dr. Jim Wright at
1227 Quince Way, Denver, 80321.

If you were quick enough to sign up for Bottle Gardens,
remember the date, May 3 at 9 a.m., Classroom B. Bring a
wide mouthed, clear glass bottle, perferably 1 gallon or
larger.

SPECIAL FIELD TRIP — Steve Cowgill has volunteered
to lead a field trip on May 17 to the Boulder area. As those
of you who may have gone before know, this area is one
where many different species may be seen in a relatively
small area. According to Dr. Weber, plants have been moving
into and out of the Colorado Front Range ever since it was
lifted up. The Rocky Mountains have been at once a
highway and a barrier to migration so that the area is an
intricate mosaic of altitudes, slopes, exposures, microclimates
and ecological gradients of all sorts and the distribution of
plants mirrors this complexity.

Meet at 8:00 a.m. at 909 York Street, or at the parking
lot of the National Center for Atmospheric Research at
9:00 a.m. Limit 20, please call and sign up.

Does the name Albizzia strike a chord? If not check
Bailey’s The Standard Cyclopedia of Horticulture. It is a
surprise to find that tree listed in The Trees of Boulder by
Campbell Robertson. Mr. Robertson is working on a new
survey of trees of Boulder. The ultimate goal is to cover all
woody species but this draft form lists only deciduous tree
form specimens; needle-leaved trees are not included; shrubs,
and shrubby form of species, which occur only sometimes in
tree form, are not listed, and the coverage of fruit trees is
only partial. Also, specimens of less than 2 inch trunk
caliper are usually not shown.

It is listed at this time with the hope that other
interested persons in Boulder will add to Mr. Robertson’s
endeavors, by detecting errors in locations or identifications;
by calling attention to better specimens or by discovering
additional rare species.

The Trees of Boulder is available at the Chamber of
Commerce in Boulder for 75 cents.

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TREE OF THE MONTH

European Beech, Fagus sylvatica

This tree is featured, not because it is recommended for
the area, but rather because it is an unusual tree that can be
grown if one uses due care in getting the tree established,
and pays particular attention to the soil.

The European Beech is a striking tree both winter and
summer. In winter, it stands out because of the smooth bark
and in summer, because of its glossy, dense foliage. The one
pictured is located at 113 East 3rd in Denver. The trunk is
about 24’ in diameter and the tree is over 40 feet tall.
Another fme specimen is located at St. John’s Cathedral at
13th and Clarkson Streets in Denver. All of them found in
Denver so far appear to be of the Copper Beech variety, F.
s. atropunicea. This variety is noted for the coppery-red
spring growth.

There are many other forms of European Beech but
apparently they have not been tried in Denver. Included in
this group is the weeping form up-right, fastigita form with a
lombardy poplar-like growth and a fern leaf variety which
has deep-cut margins. Cold hardiness does not seem to be a
big problem as it will thrive in our winter and alkaline soils.
Perhaps this is why most of the Beech found in Denver are
in the older, more acid soils.

Even though this species is not generally recommended
for this area, the hobby gardener may wish to give it a try,
in order to have something distinctively different in the
yard.

The Men’s Garden Club will present a Symposium on
May 17, from 9:30 to 12 noon in Horticulture Hall. At this
session, open to all, many timely topics will be discussed.
For example, Dick Hannigan will teach about Growing
Vegetables on Your Lanai (note move from A and 9 o’clock
as listed in April Newsletter). Other informed and

stimulating speakers will be on the program to discuss
Organic Gardening, Pests Diseases and Other Controls, and
Lawn Care and Management.

Plan now to attend.

Region Twenty of The American Iris Society will
present the 1975 IRIS SHOW AND SALE at the Horti¬
culture Hall, 1005 York Street, Denver Botanic Gardens.

Saturday, May 31 1:30 PM to 5:00 PM

Sunday, June 1 9:00 AM to 5:00 PM

The public is invited without admission charge to view
the show iris and/or enter horticultural stalks and/or arrange¬
ments.

All Welcome!

Green Thumb Newsletter is published monthly by Denver Botanic Gardens,
Inc., 909 York Street, Denver, Colorado 80206. The Newsletter is included as a
benefit of membership in the Denver Botanic Gardens, regular membership dues
being S 1 0.00 a year. Items for publication are welcome. The deadline for copy to
the editor is 2:00 p.m. on the 10th of each month preceding publication.

Editor — Margaret Sikes, 297-2547, Ext. 23.

Greet) ihutlll) jfctysfeffer DENVER botanic gardens, i n c.

Copyright 1975

NUMBER 75-6 JUNE 1975 TELEPHONE 297-2547

GARDENING TIPS FOR JUNE

June at last! After a very slow warm-up in spring and
what seemed to be an early start and then a very sudden
slow-down, perhaps, now we can sit back and enjoy watch¬
ing our gardens grow a little bit.

At the time of writing this column, weather conditions
indicate a continued dry period with below-normal precipita¬
tion, frequent gusty, drying winds, combined with below-
normal temperatures. In the March newsletter, I touched on
drought and the under abundance of moisture in the future.
Since that time, we have had plenty of snows in the
mountains to rebuild our reserves of water. At the same
time, I think we should be concerned about water and the
conservation of water. The Denver Water Department has
published a very excellent brochure entitled, “44 Ways To
Be Water Wise.” In case you have not received it or have not
read it, I would like to point out some of the things that
were mentioned, particularly as it pertains to home
gardeners.

• Instead of using a hose to clean the sidewalks and to
remove leaves from the lawn, use a broom and a rake

• Improve Denver’s typically poor soils before planting
lawns, trees, shrubs, flowers and vegetables. Use organic
matter such as compost, peat moss and barnyard manure
rototilled into the soil at least 6 inches deep. These
amounts will help to hold water and also give you more
healthy plants.

• Areas of steep slopes, where turf grasses may be difficult
to water, should be considered a good place to use one of
the many kinds of ground covers. Information of ground
covers available can be obtained from any one of the
Colorado State University Extension Offices.

• Gravel, bark or wood chips over thick plastic sheeting can
be utilized in areas that dry out quickly. Avoid too large
an area of plastic, however, as it will tend to increase
summer heat.

• Use plants adaptable to sun-wind exposure and a mini¬
mum of water. Included are the following: Hackberry,
Russian-olive, the pines, Siberian Peashrub and Buffalo-
berry.

• Soils that are of a heavy clay texture will take water
more slowly than sandy soils. Learn to apply water with
the proper sprinkler so that watering is done at the
proper rate rather than allowing it to run off and down
the gutters.

• Lawn areas on south sides will need watering more
frequently than on north sides. If you have a sprinkler
system, try to adjust your watering schedule to meet the
needs of the turfgrass.

• Rather than watering a lawn on an every-other-day
scheme, let the lawn tell you when it needs water. When
grass turns a dull gray-green, or when foot prints remain
in the grass, it’s time to water. Watering before this
happens not only wastes water, but will tend to en¬
courage more shallow rooting.

• Use root watering devices such as the Ross Root Feeder
for shrubs, trees and other deep-rooted plants. This puts
the water where it is needed with virtually no waste. In
addition, it will help to aerate heavy clay soils.

• Keep the lawn mowed to a reasonably tall height, prefer¬
ably no less than one and three-fourths inches. A lawn
cut too short encourages water loss as well as weeds.
Weeds compete for water.

• Use mulches such as wood chips, coarse compost and
other materials that will not pack tightly. A list of
suitable mulches is available through the county extension
offices.

The point I like best in the brochure is this:

• Forget about watering streets, walks, and driveways. They
won’t grow a thing!

Be bug wary! In June, many of the most serious insect
pests begin to take their toll on garden plants. If you own a
Spruce or Fir and particularly if you live in the east and
southeast parts of Denver, be on the lookout for the
devastating Tussock Moth. The problem is sufficiently
serious to warrant an area-wide campaign which was con¬
ducted in May by the Campfire Girls in cooperation with
Trees for Today and Tomorrow and the Colorado State
University Extension Service.

The best way to detect Tussock Moth is to stake down
a 12’ x 12’ sheet of white plastic or other durable material
beneath the trunk of the tree and check for signs of chewed
needles and yellow, sand-like droppings from the caterpillars.
Should you find this evidence, the trees should be sprayed
immediately. On very large trees, they will need to be
sprayed commercially. For smaller trees, call 355-8306 for
details on control.

Cankerworms, caterpillars and leaf rollers always seem to
be present at this time and are best controlled by using
Malathion or Diazinon. With the exception of leaf rollers,
Sevin will also control most caterpillars and is a rather safe
pesticide to use even in the vegetable garden. The crawler
stage of many scale insects is best controlled at this time,
again using -Malathion or Diazinon. They will be particularly
common on Euonymous, Lilac, Dogwood, and Aspen. As
with all pesticides, be sure to read the label and follow all
directions carefully.

This column will not have space to go into all the other
insects you might run into but the county extension offices
of Colorado State University will be able to answer any
questions you might have in your particular area.

The main thing to keep in mind is that the insect should
be identified first, before grabbing the sprayer. Determine
whether it is really a problem and that it warrants control.
Many insects that appear to be a real problem, turn out to
be beneficial; or at least not in sufficient numbers to warrant
using pesticide control measures.

Dr. J. R. Feucht

Thank you so much!

The 1975 Plant Sale has gone down in Botanic
Gardens history as the greatest yet! To all of you who
gave of your time, your energy, your talents, your
enthusiasm, your plants — even your financial
resources — the Board of Trustees, the Staff, and the
Membership of the Denver Botanic Gardens offer warm
thanks. Our sincere congratulations to all and
especially to Chris McCall, this year’s chairman.

Assistant Director Visits Nursery Meetings

During the spring and early summer of 1975 the Denver
Botanic Gardens will be planting a wide variety of trees,
shrubs and flowers.

To aid in the purchase of these, I flew to Chicago,
Illinois, to attend one of the largest nurserymen’s buying
conventions in the country — the Mid-American Nursery
Conference. This was held at the Arlington Park Exposition
Center in Arlington Park, Illinois. At this meeting were over
200 exhibits from all over the United States, Canada and
Puerto Rico. The exhibits ranged from actual nursery stock
(trees, shrubs, perennials, etc.) to nursery supplies and
equipment. Also, there were many novelty items for the
retail garden center. More than 3,000 nurserymen, land¬
scapers and garden center personnel attended this meeting.

There were business and education sessions at this
convention, but the main purpose was to buy and sell
nursery stock on a wholesale basis. This was the primary
purpose for my trip. Over $11,000 in trees and shrubs and
evergreens were purchased for our planting this spring. Much
of this plant material was personally selected in the growing
fields of several nurseries in the area. This insures a better
quality plant than one that is ordered by mail or phone.

After my return from Illinois, the Rocky Mountain
Regional Turfgrass Conference was held at Fort Collins the
following week. This was a two-day educational meeting.
Many new ideas concerning turfgrass culture were presented.

Some of the items mentioned were the use of a new
growth retardant for lawn grasses, proper timing of fertilizers
to conserve on water use, varieties of grass more suited to
drought or dry conditions and motivation of employees.

These and other ideas gleaned from the various speakers
will be put into practice here at Denver Botanic Gardens.

Right on the heels of this conference was the Colorado
Nursery & Shade Tree Conference at the Regency Inn in
Denver. At this meeting were 22 exhibitors and several hundred
nurserymen and tree experts from several western states.
This was a very fine educational meeting, particularly for
myself, since I am a recent transplant to this area from
Illinois (one of the wet states). One of the most exciting
sessions (at least for myself) was the one on “Drip
Irrigation.” I feel that this is really an important concept in
a dry climate such as occurs here along the front range. The
essential idea is to apply water slowly to the soil in amounts
that can be used up by the plant each day and not to water
adjacent areas. This system was pioneered in Israel and now
used extensively in California. It is a very good water
conservation system. We hope to have a homeowner type
system installed for public inspection this summer.

I met a few of the Colorado nurserymen at this meeting
and am looking forward to getting acquainted with more of
them.

All in all, it was a very busy two and one-half weeks
wliich was spiced with moving all the household goods from
our home in Illinois.

Some very interesting ideas have been formed by these
meetings and we hope to implement some of these in the
coming months so that any of the interested public will gain
some benefit also. Please visit the Gardens in late June and
see our progress and possibly pick up some ideas of your
own. Glenn Park

Assistant Director

AND ANOTHER WELL TRAVELED STAFF MEMBER

Solange Huggins, librarian, Helen Fowler Library, has
attended an Interlibrary Loan Workshop in Aspen and a
meeting of the Council on Botanical and Horticultural
Libraries hosted by the Missouri Botanical Garden in St.
Louis.

Something New at the Gardens

Since there is so much interest in vegetable gardening, a
new area has been developed showing how to grow a wide
range of vegetables and to try the latest introductions in the
Denver area. This will give valuable information to the home
owner and apartment dweller at a time when they are
looking for ways to cut food expenses by growing their own
vegetables.

The area may be found to the west of the Outdoor
Gardener’s workshop adjacent to the workshop patio west of
the Conservatory.

Railroad ties have been used as retaining walls to add
interest to this area for we think building this garden at
several different levels will give a pleasing effect. Also, a few
container grown vegetables will be placed at various spots in
the garden.

One other item of note — there will need to be a fence
around this area to prevent animals (two and four legged)
from marauding the garden. A decorative four foot high
fence will keep out all but the most determined ones. A
pathway composed of some sort of mulch material (bark
chunks, gravel, wood chips, etc.) will also add a distinctive
touch to the area.

As a further refinement, the new drip irrigation method,
which has been widely acclaimed as a water saving device,
will- be demonstrated here.

One of the reasons for this type of project is to fill an
early recognized need. In Colorado As An Agricultural State
published in 1883, the statement is made:

“Agriculture in Colorado is an entirely different pursuit
from what it is in the Eastern States, and the farmer
who comes to the State and enters upon the cultivation
of the soil in the style he has been accustomed to, will
find that failure is more likely to result from his labors
than success. He has much to unlearn.”

Look at our plot the next time you are visiting the
Gardens. Also go to the Gift Shop where for 50 cents you
may buy George Kelly’s book “Good Gardens with Less
Water in Colorado. ”

* * * *

The season for travel is here. For those of you fortunate
enough to be planning a trip to Europe the film on June 21
is a must. “European Gardens” will only take 20 minutes of
your time but will help prepare you for some of the beauty
spots you may visit. Plan to view this at 1:30 p.m. June 21,
Classroom C. Free.

DENVER BOTANIC GARDENS
CALENDAR OF EVENTS
JUNE, 1975

JUNE

1)

9:00 a.m.

Education Building — Horticulture Hall

Iris Society Show & Sale

OPEN TO PUBLIC 9:00 a.m. - 5:00 p.m.

3)*

10:00 a.m.

Education Building - Herbarium

Herbarium Committee Meeting

3)*

1 :00 p.m.

Botanic Gardens House — Dining Room

Editorial Committee Meeting

3)

7:30 p.m.

Botanic Gardens House — Dining Room

Denver Audubon Society (Wildlife Workshop)

3)

7:30 p.m.

Education Building — Lecture Room “B”

Denver Bonsai Club

4)

9:00 a.m.

Education Building — Horticulture Hall

Colorado Water Color Exhibition Show
(Through June 19th)

4)*

11:30 a.m.

Botanic Gardens House — Main-
Dining & Kitchen

Junior League Transfer Sustainer Tour &

Box Lunch

4)

7:00 p.m.

Education Building — Horticulture Hall

Sierra Club

4)*

7:00 p.m.

Education Building - Lecture Room “B”

House Plant Class — Mr. Dave Woodward

5)

7:45 p.m.

Education Building — Horticulture Hall

Denver Orchid Society Meeting

6)

9:00 a.m.

Education Building - Horticulture Hall

LEADERSHIP DENVER

7)*

9:00 a.m.

Education Building — Lecture Room “B”

Rocky Mountain Belles —

(Judging Class, Instructor: Mrs. Emma Lahr)

7)

9:00 a.m.

12th & Baseline — Boulder

Tree Walk — Mr. Campbell Robertson

8)*

9:00 a.m.

Education Building — Lecture Room “B”

♦ ♦♦♦♦♦♦

Rocky Mountain Belles (Judging Exam)

♦ ♦ ♦ ♦

9)

7:30 p.m.

Education Building — Horticulture Hall

Colorado Mycological Society

9)

7:30 p.m.

Botanic Gardens House — Main Room

Sierra Club (Wildlife Workshop)

10)*

9:30 a.m.

Education Building — Lecture Room “B”

Civic Garden Club — Division “C”

10)*

4:00 p.m.

Botanic Gardens House — Dining Room

Executive Committee Meeting

ID

9:30 a.m.

Education Building — Lecture Room “A”

“Pruning” — Mr. Glenn Park

11)*

7:00 p.m.

Education Building — Lecture Room “B”

House Plant Class — Mr. Dave Woodward

11)*

7:30 p.m.

Botanic Gardens House — Dining Room

Landscape Industry Council

12)*

3:30 p.m.

Botanic Gardens House — Dining Room

Development & Public Relations Meeting

12)

7:00 p.m.

Education Building — Lecture Room “B”

Sierra Club — Conservation Committee

12)

7:30 p.m.

Education Building — Horticulture Hall

Slide Show — “Colorado’s Wonderland of Flowers”
Mr. L. Long

12)

8:00 p.m.

Botanic Gardens House — Main-
Dining & Kitchen

Denver Rose Society

13)*

9:30 a.m.

Education Building — Lecture Room “A”

National Jr. Horticulture — “Woody Plants”

13)

7:30 p.m.

Botanic Gardens House — Main-
Dining & Kitchen

Denver Dahlia Society

14)

10:00 a.m.

Education Building — Lecture Room “B”

♦ ♦♦♦♦♦♦

Colorado Organic Grower’s & Marketer’s
Association

♦ ♦ ♦ ♦

17)

7:30 p.m.

Education Building — Horticulture Hall

Sierra Club

18)

9:00 a.m.

Botanic Gardens House — Parking Lot

PLANT LIFE FIELD TRIP - DR. BRUNQUIST

18)*

10:00 a.m.

Education Building — Lecture Room “C”

Children’s Garden (Lecture)

18)*

7:00 p.m.

Education Building — Lecture Room “B”

House Plant Class — Mr. Dave Woodward

18)

7:30 p.m.

Education Building — Herbarium

Denver Botany Club

19)*

10:00 a.m.

Botanic Gardens House — Main Room

Around the Seasons Meeting

19)

7:30 p.m.

Education Building — Lecture Room “C”

Organic Gardening Club of Denver

20)

9:00 a.m.

Education Building — Lecture Room “C”

“Cacti” — Instructor: Mrs. Virginia Simmons

20)*

9:30 a.m.

Education Building — Lecture Room “A”

National Jr. Horticulture — “Woody Plants”

CALENDAR OF EVENTS FOR JUNE (Continued)

21)

8:00 a.m.

Red Rocks Park

“Cacti” Field Trip

21)

Education Building — Horticulture Hall

Denver Bonsai Club — Show & Exhibition
OPEN TO PUBLIC - 10:00 a.m. - 5:00 p.m.

22)

Education Building — Horticulture Hall

♦ ♦♦♦♦♦♦

Denver Bonsai Club — Show & Exhibition
OPEN TO PUBLIC - 10:00 a.m. - 5:00 p.m.

♦ ♦ ♦ ♦

24)

8:00 a.m.

Cheesman Park

Tree Walk — Mr. Ken Hostetler

24)

7:30 p.m.

Education Building - Lecture Room “C”

Gladiolus Society Meeting

25)*

1 1 :00 a.m.

Botanic Gardens House — Main-
Dining & Kitchen

Sunbonnet Garden Club

25)*

7:00 p.m.

Education Building — Lecture Room “B”

House Plant Class - Mr. Dave Woodward

25)

7:30 p.m.

Education Building — Lecture Room “C”

Colorado Open Space Council
(Wilderness Workshop)

26)

7:00 a.m.

Botanic Gardens House — Parking Lot

Field Trip to Mt. Goliath

26)

7:30 p.m.

Education Building — Lecture Room “A”

Capitol Hill United Neighborhood

26)

JULY

7:30 p.m.

Botanic Gardens House — Main-
Dining & Kitchen

♦ ♦♦♦♦♦♦

Men's Garden Club of Denver

♦ ♦ ♦ ♦

1)*

10:00 a.m.

Education Building — Herbarium

Herbarium Committee Meeting

1)*

1:00 p.m.

Botanic Gardens House — Dining Room

Editorial Committee Meeting

1)

7:30 p.m.

Botanic Gardens House — Dining Room

Denver Audubon Society (Wildlife Workshop)

3)*

7:30 p.m.

Education Building — Lecture Room “C”

Colorado Open Space Council (Board Meeting)

*For members or enrollees only.

JUNE CLASSES

Mr. Glenn Park, Assistant Director of the Denver
Botanic Gardens, will teach the fundamentals of Priming on
June 11 at 9:30 a.m. in Classroom A. Free.

Our next two sessions for those interested in the
National Junior Horticulture program will be on June 13 and
20. Both will study the Summer Characteristics of Woody
Plants and will be taught by Dr. Feucht. Meet at 9:30 a.m.
in Classroom A. Free but limited to students under 21 years
of age.

Field Trips will continue on the third Wednesdays of
each month throughout the summer. Dr. Brunquist meets
those interested at 909 York at 9 a.m. On June 18 plan to
join us. Free and all welcome.

Many different plant families in different parts of the
world have developed special features of desert dwelling
plants. Some of these adaptations such as thick leafless stems
covered with waxy coatings and armed with spines are
devices which seem typical of cacti. Therefore, a casual
layman would probably be confused. Come on Friday, June
20th, to Classroom C at 9 a.m. and learn the features of
Cactaceae. All welcome. On June 21, the first 20 people to
sign up may study cacti in the field. They will meet in the
Red Rocks Park at the Trading Post at 8 a.m. Free but
please sign up after June 9.

Another morning walk is scheduled on Tuesday, June
24. At this time we will Identify Trees and look for evidence
of insect damage and disease. Meet at 8 a.m. at the Greek
Temple at Cheesman Park. Free.

Finally, the first Field Trip to Mt. Goliath will be a
work day to help replace labels and signs. Of course it will
also provide a fine opportunity to see early alpine flowers.
Meet at 7 a.m. at 909 York or at 9 a.m. at Echo Lake
Lodge on June 26. Free, bring lunch, limit 20. Please, no
sign ups until June 12.

Special Treat

Mr. Campbell Robertson whose work on trees was
mentioned in the last newsletter, will lead a Tree Walk in
Boulder on June 7! Meet at 9 a.m. at 12th and Baseline.
Free and all welcome.

Information has been received about the summer
offerings of the Rocky Mountain Nature Association.

Rocky Mountain National Park presents an ideal
outdoor laboratory in a natural environment for study of
geological processes and products, animals, plants and their
ecosystems. Recognizing this fine opportunity, seminars in
ecology, geology and related fields have been given in the
Park for the past thirteen summers. The major portion of
the day is spent observing in this “living museum” and then
shorter indoor sessions follow each day’s field activities.
Distinguished ecologists may present evening lectures to
complement the daytime work.

The classes to be offered are: Developing Awareness
through Drawing, Mr. Herb Thomson; Rocky Mountain
Ecosystems, Dr. Richard G. Beidleman; Bird Ecology, Dr.
Gustav A. Swanson; Wildlife Management, Dr. Douglas L.
Gilbert; Plant Identification, Dr. Miriam L. Denham; Alpine
Ecology, Dr. John L. Marr; Mountain Geology, Dr. Robert
B. Johnson; and Advanced Mountain Geology, Dr. Robert B.
Johnson. For further information on fees, 'registration and
college credit, please write:

Seminar Coordinator

Rocky Mountain Nature Association, Inc.

Rocky Mountain National Park
Estes Park, Colorado 80517

Thorne Ecological Institute has announced its Ninth
National Seminar on Environmental Arts and Sciences, June
22 to 26 in Aspen. This year thirty-five leaders in industry,
business, education, government and labor will explore
“Harmonizing Socio/Economic Needs and Environmental
Imperatives.”

For further information please contact:

Patricia L. Jensen, Seminar Coordinator
Thorne Ecological Institute
2336 Pearl Street
Boulder, Colorado 80302

WILDFLOWER PICTURES !

“Colorado’s Wonderland of Flowers” will be presented
on June 12 at 7:30 p.m. in Horticulture Hall.

This one hour program was produced by Lucian Long
using a two screen, four projector system with sound which
he has assembled for the purpose. Two tape recorders with
separate dissolve units permit continuous showing of over
600 rare slides from several parts of the world. Many of
these slides were taken by the late Dr. John C. Long of
Denver during the last 35 years. Special emphasis is focused
on groups of Colorado wild flowers in the ecological zones
and the effect of glaciers in establishing such zones.

Long is an accomplished photographer and has had

extensive experience in program production with several
Denver radio stations. During the past five years he has

constructed a native garden in Monument Valley Park as a

project of the Horticultural Arts Society of Colorado

Springs.

Come see these lovely pictures which will be presented
free for members. Please show your card at the door; all
others please pay $2.00 for admittance.

By Luella Deam

The Colorado Watercolor Society will have the opening
of its annual all water media exhibit at the Denver Botanic
Gardens, 1005 York Street, on Thursday, June 5. The show
will be on view in the Horticultural Hall daily from 10 a.m.
to 4 p.m. and will close on Thursday, June 19. There is no
admission fee.

Robert Strohmeier, professor of art at the Metropolitan
State College, will be the juror for the show.

Paintings in the exhibit are for sale and approximately
sixty-five paintings will be on display. All members in the
Colorado Watercolor Society are actively engaged in painting
and in promoting contemporary art techniques.

This organization has been in existence for twenty-one
years and this is the fourth year that the group has been
invited to display its annual all water media show at the
Denver Botanic Gardens.

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Help please!

Knowledgeable volunteers are needed to serve as “Dr.
Green.” This feature of the Gardens has been very popular
with the public (so much so that the staff has been
swamped).

Questions are fielded by phone and in person and range
all over the plant world — house plants, ornamentals,
vegetables and lawns.

If you can’t answer every one, don’t worry. All staff
members have been stumped too, necessitating a visit to the
Library and a return call to the questioner.

The hours of the service are 1 to 3 p.m. every Tuesday
and Thursday but of course we would appreciate any time
you might spare. If you can help please call Glenn Park,
297-2547, ext. 4.

*******

The Denver Bonsai Club will present its annual
exhibition of trees in miniature at the Denver Botanic
Gardens, Saturday and Sunday, June 21 and 22, from 10
a.m. to 5 p.m. daily.

Over 100 trees ranging in age from several months to
300 years old will be on display at this popular show, with
demonstrations to be presented each day.

The public is cordially invited to attend.

Mark Your Calendar!

A reception will be held on July 7 at 7 p.m. at 909
York in honor of Cythna Letty Forssman. Mrs. Forssman,
who has recently retired from the University of Pretoria,
South Africa, is a well known plant illustrator. Exhibits of
her work have been shown in Capetown, Johannesburg and
London.

Examples of her art will be on display at the event. All
interested people are urged to come and meet this dis¬
tinguished botanical artist.

The Tour Guides Committee of the Associates has
announced the summer schedule of tours. Guided tours will
be provided for fourth grade and up and for adult groups at
10 a.m. on Tuesdays and Thursdays in July and August. This
service of the guides is always popular so tours must be
booked ahead of time.

Our thanks go to Ellen Waterman who has scheduled the
guides for this past academic year. It is a big job (692 tours
in all) and has been handled in a most pleasant and efficient
manner. Bev Hanselman has accepted this assignment
starting in summer and all are looking forward to helping her
with this important aspect of the Associates program.

Denver Rose Society Show

The Denver Rose Society will present its Annual Show
on June 22 at the Colorado National Bank. The hours are 1
to 5 p.m. and many beautiful blooms and arrangements will
be displayed. Experts will be on hand to help answer
questions and as a special feature, people will be asked to
identify plants. The first 50 winners will be awarded
miniature roses as prizes. All welcome.

This spring over 400 rose bushes were planted in three
areas of the rose display garden which is located in the
center portion of the garden. You will see such old favorites
as ‘Queen Elizabeth’ and ‘Peace’ along with quite recent
introductions ‘Perfume Delight,’ ‘Medallion’ and ‘Arizona.’
Many other All-America Rose Selection varieties are also
presented: ‘Chrysler Imperial,’ ‘Lowell Thomas,’ ‘Tropicana,’
‘Command Performance,’ ‘Camelot’ and ‘Granada.’ The pinks
have it with ‘Show Girl,’ ‘Katherine T. Marshall,’ ‘Pink
Peace’ and novel ‘Candy Stripe.’ Blends include ‘Ann Letts,’
‘Chicago Peace’ and ‘Sunrise-Sunset.’

Green Thumb Newsletter is published monthly by Denver Botanic Gardens,
Inc., 909 York Street, Denver, Colorado 80206. The Newsletter is included as a
benefit of membership in the Denver Botanic Gardens, regular membership dues
being $ 1 0.00 a year. Items for publication are welcome. The deadline for copy to
the editor is 2:00 p.m. on the 10th of each month preceding publication.

Editor - Margaret Sikes, 297-2547, Ext. 23.

GfdCJj TbUfllh JfGtySktfcr DENVER botanic gardens, i n c.

Copyright 1975

NUMBER 75-7 JULY 1975 TELEPHONE 297-2547

GARDENING TIPS FOR JULY

July is a month when a lot of people are on a vacation
but the yard still must be taken care of and if you are going
to be away for more than a week, the following tips will
help to insure that your yard will be in reasonably good
order when you return.

It is surprising how a few weeks of neglect will turn
your yard into a ragged ruin that will require many hours of
hard work to return it to its original beauty.

Another good reason for keeping your yard in good
maintenance while you are away is for the protection of
your home and contents. A neglected yard is an open
“advertisement” to prowlers that the house is vacant.

Mowing, general weeding of the flower beds, and water¬
ing can be entrusted to the “kid next door” if he is properly
instructed before your departure.

If spraying for pests is necessary during your absence,
make arrangements with a reputable arborist or landscape
maintenance firm. Many have found it more economical in
the long run, and can put their minds more at ease by hiring
a commercial maintenance firm to do all yard maintenance
during their absence.

If you do hire the neighbor boy, use the followmg as a
guide in giving him instructions:

1. If he is to use your lawn mower be sure that he is
instructed on how it operates. If the mower is of the 2-cycle
type requiring a gasoline-oil mixture, make sure he knows
how to make the mix or supply him with an adequate
quantity of the fuel.

2. If he uses his own lawn mower, make sure that it is
set for the proper height of cut.

3. Mark or point out all hazards in the lawn area that
would be damaging to the mower such as sprinkler heads,
faucets and water meters that protrude above ground.

4. If you have him water your lawn and flower beds,
suggest to him the best system for setting the sprinklers to
give good coverage and indicate the length of time each
sprinkler should be set in one spot.

5. If you are away more than two weeks you will need
to instruct the boy on pulling weeds from the flower beds.
It is always safest to clearly mark any of your flowering
plants that might be mistaken for weeds.

6. Always make arrangements with an adult neighbor
that the boy may contact, should he run into serious
trouble.

Bugs in the Vegetable Garden

At this time of year insects can be devastating to all
garden plants but are probably tire most noticeable in
vegetables. If you have beets, chard, or spinach, you might
be experiencing damage to the foliage from the leaf miner.
This is caused by the larva of a small fly that burrows
between the upper and lower surfaces of the leaf and
certainly does not make the foliage desirable to eat. The leaf
miner has several life cycles a year so it requires frequent
control. The best control available is malathion applied at
weekly intervals or Diazinon applied about every 14 days. In
both cases be sure to check the label for the waiting period
required following spraying before eating the tops.

The tomato homworm will begin its activity this month,
although it is not noticed until August. If you do not wish
to use pesticides, the worms can be picked off as they are
found. It takes good eyes to find them. If a sufficient
number are missed to cause damage, spray with Sevin
applied every two weeks will usually keep them in check. On
tomatoes, Sevin has only a one day waiting period. After
that the tomatoes are safe to eat. Sevin is also an excellent
material to use for the control of Cabbage worm and other
caterpillar-types of insects. It does, however, require a longer
waiting period before eating the crop when used on
vegetables other than tomatoes. Again, be sure to check the
label and follow directions carefully.

Slug Control

Slugs got an early start this year because of the cool,
moist weather in late May and early June. Because slugs like
cool, moist conditions, one of the best ways to control them
is allowing the soils to dry out a little bit between waterings.
Slugs also do not like to crawl across rough soil. If the soil is
kept cultivated and a bit on the dry side you do not have as
much trouble with this pest.

A few years ago, a USDA scientist discovered that beer
attracts slugs. A little bit of beer in a coffee can plunged
into the ground so that the rim is level with the surface of
the soil will help trap them. Select a shaded area where the
soil is apt to remain damp for a longer period of time in
order to have the most satisfactory results.

The common preparation for control of slugs is metalda-
hyde. This product comes in pellet form and gives good
control but it is usually very short-term. Because this
chemical is quite toxic to pests, it should be placed where
dogs and cats cannot get to it. One trick is to put some
pellets in tin cans which have had both ends removed. Place
the cans on their sides beneath shrubs or other places where
they would not be too accessible to pets.

In last month’s gardening tips, we spent a lot of time
talking about wise watering. Despite the fact that the
reservoirs are full and we have had a sufficient amount of
snow since then to insure a good supply of water this year, I
hope you will follow the advice in the publication by the
Denver Water Board, particularly now that we are in the hot,
dry season. This time of year there is a lot of water wasted
because there is a tendency to water every time the soil is
dry on top. Before watering, dig down a few inches to see
what the supply is like. After all, that’s where the roots are.
This will help to control those pesky slugs.

Come Admire the Daylilies

Since the Denver Botanic Gardens started its Hemero-
callis Garden three years ago, 350 cultivars have been
donated to the collection. Of this group, only 1 1 duplicates
have been received. Members of the Society added 21 new
varieties this spring and additional prize winning plants are
expected soon. The first daylily bloomed on May 19 this
year, but generally the height of the season is July and
August. Colors range from near white to dark red with all
shades in between.

Our thanks to George Paul Watts, Past President of the
American Hemerocallis Society, Harry Kuesel, Miss Edna
Lankart, Jack Riley, and Gilbert Wild and Son.

JULY CLASSES

Are you busy on July 9th? If not, now is a great time
to visit Mt. Goliath for spring is just beginning at this
altitude. The whole trip including a 1-1/2 mile walk on the
M. Walter Pesman Trail can be done in 6 hours. Meet the
group at 7 a.m. at 909 York or 9 a.m. at Echo Lake Lodge.
Sign ups after June 27, please. Limited to the first 20
names. Remember to take Susie Ash’s Mt. Goliath Guide,
available in the Gift Shop, for important information on the
area and its flora.

Annuals will be discussed on Tuesday, July 15 at 9 a.m.,
Classroom A, by Glenn Park. Tliis is offered as part of the
National Junior Horticulture Program and is open to any
interested students under 21 years of age.

Dr. Brunquist will lead his Field Trip on Plant Identifi¬
cation on July 16. Meet at 909 York at 9 a.m. Free. Please
share gasoline expenses and carry a lunch.

The trip to St. Mary’s Glacier will provide another
opportunity to view high altitude plants. Often we see over
50 species, including some rare beauties, at this spot. Join us
on July 19, 7 a.m. at 909 York or 8 a.m. on Exit 48 on
1-70. No sign ups before July 7, please. Also remember if
you are not one of the first 20 on the list, put your name
on the waiting list. If any of those accepted cannot attend,
and if they notify us of that fact, we will call you.

Our July film will fit in nicely with our scheduled trips
to Mt. Goliath and to St. Mary’s Glacier. “Above the
Timberline” will be shown on July 12 at 1:30 p.m.,
Classroom C. Free.

Finally, all welcome to Identification of Common Mush¬
rooms. This class is set for Saturday, July 26, 9:30 a.m.
Classroom C. Free.

Advance notice has been received about a lecture by Dr.
Alexander Smith, the eminent mycologist. This is planned
for August 4 in the evening. More information in next
newsletter.

THANK YOU for helping us to do it again! Each of you and
your friends who sent in books for this year’s Used Book
Sale can take a share in the satisfaction we feel at being able
to add just over $2500 to the Helen Fowler Library’s budget
for May 75-May 76 for new books! This is an increase of
about 45% over our last year’s figure, but we’re just several
steps ahead of inflation. We’re already collecting for next
year’s sale so please do remember to send us your unwanted
books, magazines, art prints, phonograph records of all
speeds, old postcards, and ask your friends and neighbors to
do the same.

Now some bad news — the only general encyclopedia in
the Library reference section is the 1966 Americana. We
discovered several weeks ago that volumes 10, 16 and 20
have been “borrowed”. We keep hoping they will be put in
the bookdrop at the Gate, but so far no luck. We covet the
new Britannica, but the Booksale funds, and the monthly
contribution the Library receives from the Associates of the
Denver Botanic Gardens are designated for the purchase of
new acquisitions, not replacement of lost or stolen works. Is
there a generous soul among you who would like to update
our now incomplete reference encyclopedia?

*********

And from Spores Afield :

A mushroom is a vegi-table
To detect if you are able.

You can’t tell them when you meet them;
You can tell them when you eat them!

If in heaven you awaken,

Then you know you were mistaken
And the mushroom you have eaten
Ain’t the one you should have et!

A new display on Mineral Water Gardening has been
arranged on the steps going up to the sun deck at 1005
York Street. Mr. Norton Novitt, hydroponicist, is grow¬
ing appropriate tomatoes in units which are suitable
for indoor or outdoor use, window sill or patio. Labels
explaining this process are posted next to the units
and further information is available in the Helen Fowler
Library.

1975 GARDEN TOUR

The 1975 Garden Tour will be held July 23rd from
10:00 a.m. until 6:00 p.m. The gardens chosen are:

1) Mr. and Mrs. William B. Collister, 6320 E. Fourth Ave.

2) Mr. and Mrs. Joe Miller, 125 Jasmine St.

3) Miss Charlotte O’Malley, 322 Grape St.

4) Mr. and Mrs. W. Coles Hudgins, 4949 Sixth Ave.

5) The Childrens’ Garden, Mrs. Irene Vittetoe,

Instructor, Denver Botanic Gardens

6) Mr. and Mrs. George P. Caulkins, Jr., 435 Westwood

Drive

7) Mr. and Mrs. Philip R. Moore, 350 Franklin St.

8) Mr. Jim Mills, Mr. Dale Mathis, 145 Fafayette St.

9) Mr. and Mrs. John A. Moore, 315 Marion St.

The price of the tickets will be a Five Dollar Donation
to the Denver Botanic Gardens (Tax Deductible). Tickets
may be purchased at the Gift Shop, from any Botanic
Gardens Guild member, or at any garden on the day of the
tour.

Among the features of interest in the gardens chosen
this year are a large swimming pool in a casual setting, plants
grown in color-coordinated schemes, modern sculpture, large
play areas segregated with shrubbery and flowers, terraces
which are brick enclosed and used as outside greenhouses in
the summer, and a latticed arbor filtering sun over tuberous
begonias.

One of the stops on the Garden & Terrace Tour will be
the Children’s Garden. This is always an interesting (and
sometimes humbling) place to visit, for the children do a
beautiful job and generally their plants are in better condi¬
tion than our own. They do work across the street and it
shows! A poem by one of last year’s gardeners expressed her
feelings nicely:

“While hoeing and thinning and weeding,

There is something I always am needing.

As the old sun gets hotter and hotter,

A nice long cold drink of water.”

As one of the Denver Botanic Gardens’ projects for the
Centennial-Bi-Centennial, we have developed a garden in the
Walnut Hill area. This is a Children’s Garden located to the
north of Barrett School at 29th and Jackson. This venture, a
cooperative project of the Denver Public Schools and the
Botanic Gardens, incorporates a large area of land, 64 by
509 feet, but is not all under cultivation this year. Thirty-
five 3rd, 4th and 5th graders from Barrett and Columbine
Schools are busily hoeing and growing. Mrs. Irene Vittetoe
is the Supervisor and reports she is having as much fun as
the children! Drive past and see this garden.

MOUNTAIN SPLENDOR
Colorado Hosts 1975 A.D.S. Show

A tall hello to all dahlia enthusiasts from the mile high
state of Colorado. Denver will be the site of the 61st A.D.S.
National show to be held August 28th - 31st, 1975. With
several planning meetings behind us we are getting ready to
give you our biggest welcome.

The theme for the 1975 show is “Mountain Splendor.”
Registration will start on Thursday, August 28th with a
planned tour on Friday. Judging of Dahlia Show on
Saturday, with a banquet Saturday evening. Sunday will
schedule important meetings of interest to dahlia growers.

The dahlias will be exhibited at the newly planted
Denver Botanic Gardens with one of the finest exhibition
halls in our nation. The headquarters for this National
meeting will be the Cosmopolitan Hotel in downtown
Denver.

FOR MEN ONLY

Do you know about the Men’s Garden Clubs of
America? They have approximately 9,000 members around
the country in 250 clubs. Twelve local clubs are in the
Rocky Mountain region with several in the Denver area
including the Denver Men’s Garden Club which meets at the
Denver Botanic Gardens.

Benefits of Membership include a bi-monthly magazine
“The Gardener” which has many articles of interest. MGCA
also has a seed exchange program, plant study program,
information bulletin service, accredited judging school
program, award programs, and National Big Pumpkin contest
(this year’s national winner was from Briggsdale and weighed
201-1/2 lbs!).

If you would like further information about the many
interesting services of the Men’s Garden Clubs of America,
please write to:

Mr. Fred L. Goldsby, National Director
MGCA - Rocky Mountain Region
1 185 Tari Lane

Colorado Springs, Colo. 80908
Oh, and PS. Ladies are always welcome as guests.

FORESTERS SEEK HISTORIC TREES

The Colorado State Forest Service, in observance of this
country’s 200th birthday, is looking for trees of historical
significance. This is being done in cooperation with the
American Forestry Association, which will publish a book on
historic and famous trees in the United States.

Trees to be considered for inclusion in the book,
according to Ken Hostetler, District Forester, will fall into
these catagories: (1) trees associated with notable people or
with the development of the nation, (2) trees connected with
educational institutions, churches, or other cultural life of
the states, (3) trees associated with forestry or early con¬
servation efforts, and (4) trees historic or famous because of
unusual size or age.

Persons wishing to nominate trees in any of these
catagories, Hostetler said, may secure nomination blanks
from State Forest Service district office, 909 York Street,
Denver, Colorado 80206.

Despite 4 inches of snow on May 29, the Bonus Plant
Give-Away was very successful. Volunteers did their usual
fine job of coping with the unexpected, people were most
appreciative and many plants got a fine new home.

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Eastern White Pine

Pinus strobus

While not entirely adapted to all Colorado soils, the
Eastern White Pine seems to thrive in certain parts of
Denver, particularly “older cultivated soils”, but it will not
survive in the outlying areas where the drainage is poor and
soils are heavy. This pine is a five-needled species and is
distinctively unlike some of the more common three -needled
pines. It probably has the most slender needles of all, giving
the tree a very soft appearance as well as feel.

The tree shown in the picture is typical of the very
interesting silhouette which makes it highly valued for both
shade and as an ornamental tree. The older trees showing a
most picturesque growth habit can be seen in many parts of
our city. Some of the best specimens are located just off
Speer Boulevard and Marion Streets. A few excellent trees
are scattered in Washington Park and along Monaco Parkway.
This particular picture was taken along Monaco Parkway.

Before planting this tree, you should check the soils to
make sure there is good drainage. It will not thrive in a
high -alkaline soil.

Dr. J. R. Feucht

Something Nice To Anticipate!

A visiting celebrity, Cythna Letty Forssman of South
Africa, will be honored at a reception on July 7 at 7 p.m.,
909 York Street. Mrs. Forssman is a well known artist and
has done many beautiful illustrations of the wild flowers of
the Transvaal. She has recently been awarded an honorary
LLD from the University of Witwatersrand in recognition of
her outstanding achievements. Examples of her art will be on
display at the House. All interested people are most cordially
invited.

Oh, My Aching Back!

Volunteers were called on again the first week of June
when 26,000 annuals had to be planted. All sorts of colorful
blossoms can be expected this summer as flowers and leaves
of every hue are represented in the outdoor beds. Look for
such beauties as Amaranthus ‘Tricolor Splendors Perfecta’;
Basil ‘Dark Opal’; Celosia ‘Rose Empress’; Dahlia ‘Border
Jewels’; Flowering Kale ‘Red on Green’; Gomphrena
‘Buddy’; Heliotrope ‘Marine’; Impatiens ‘Orange Gem’; and
so on, throughout the letters of the alphabet ending with
Zinnea ‘Royal Purple’.

Green Thumb Newsletter is published monthly by Denver Botanic Gardens,
Inc., 909 York Street, Denver, Colorado 80206. The Newsletter is included as a
benefit of membership in the Denver Botanic Gardens, regular membership dues
being $ 1 0.00 a year. Items for publication are welcome. The deadline for copy to
the editor is 2:00 p.m. on the 10th of each month preceding publication.

Editor - Margaret Sikes, 297-2547, Ext. 23.

( ffiCljlilUfllhflCtySfelfCr DENVER BOTANIC GARDENS, INC.

Copyright 1975

NUMBER 75-8 AUGUST 1975 TELEPHONE 297-2547

Gardening Tips for August

We have talked about water the last two months,
particularly water conservation, and in this hot weather, it
may seem impossible to cut back on watering, but the
month of August is a good time to begin tapering off on
water for trees and shrubs. Not of course to the extent that
plants suffer but just enough to begin to help them harden
off for winter. This is good insurance against the
unpredictable fall weather that we might have. The past few
falls have been long and extensive without any sudden
temperature changes but those who have lived here very
long, at least since 1969 will remember that year and also
1971 when summer went to winter rather quickly and the
plants were not ready for it. Gradually reducing water on
trees and shmbs helps to slow the plants down and get them
ready for winter.

Some plants will get ready for winter no matter what.
Oaks and Lindens will start getting ready for winter in July.
This is because they are regulated by day -length rather than
by weather conditions. Trees such as walnut, soft maple,
green ash and goldenraintree and several others that tend to
put out a strong second flush of growth need a gradual

withdrawal of water to help “tell them to get ready for

winter.” It would probably also be a good idea to withhold
high-nitrogen fertilizers on such trees and shrubs.

The question is usually asked, “How do I know when a
plant has hardened off’? The easiest way is to look for sign
of woodiness in the most recent growth. You will notice a
change in color from a green to olive or brown. You can
also look at the buds. Plants that are getting ready for

winter will have set buds at the base of each leaf and at the

tips of the branchlets.

Insects in the Garden

Even though we are thirty days behind schedule in insect
activity, recent hot weather seems to have made everything
catch up all at once. Now is a good time to look for the
tomato hornworm which may already be chewing away at
your plants. It is usually first evidenced by chewed foliage
and the appearance of black droppings. Sevin does a good
job of control, or they can be picked off by hand. If you
are squeamish about doing this, you might have your sons or
daughters, or the boys or girls next door perform this task
for you. Most kids don’t mind handling such creatures.

Tomatoes and potatoes are also afflicted by another
insect known as a psyllid. The adult and the nymph stages
of the psyllid cause damage by sucking our plant juices,
leading to a condition known as “psyllid yellows.” This
usually causes a stunting or distortion of the plant with little
or no fruit set. In a slow year like one when tomatoes have
been difficult to set anyway, it would be a good idea to
control or prevent this particular pest. Malathion does a
good job. '

Caution on Pesticides

Already this year we have had some of the typical calls
regarding the use of pesticides, or I should better say
“misuse”, leading to some rather unfortunate and avoidable
mistakes. A very common occurrence is the application of a

pesticide to edible crops such as vegetables and fruits, only
to read the label afterwards and find that they cannot be
used for that purpose. One of the biggest offenders on the
market is Isotox. The formula of this pesticide has been
changed and it now contains a systemic, making it unsuitable
for use on edible crops. A warning given in the past bears
repeating. ALWAYS READ AND FOLLOW THE
DIRECTIONS GIVEN ON THE LABEL EACH TIME A
PESTICIDE IS USED.

Another common problem encountered is the misunder¬
standing on the so-called “waiting period” on edible crops
after pesticides have been used. Because the waiting period
of Sevin is only one day on tomatoes does not mean it is
just the same on other vegetables. Sevin used on cauliflower
or head lettuce will require a three-day waiting period. The
law requires that the label carry clearly printed instructions
on each container of pesticide. ALWAYS READ THAT
LABEL!

Spidermites

Hot weather always brings out an increase in spidermite
activity. Unfortunately, the damage is often done before the
mites themselves, which are rather small in size can be
detected. Make it a practice to check your plants by holding
a sheet of white paper beneath the branch and shake it
vigorously. The presence of mites will be indicated by little,
tiny “dots” appearing on the paper. Kelthane and similar
insecticides will bring them under control. If you have been
using a lot of Sevin, Mythoxychlor, or Chlordane without
combining them with a miticide, you will probably be
experiencing a build-up of spider mites. This is because these
products have little effect on spidermites and they kill off
natural predators. Therefore, if you wish to control the
mites, it is generally a good idea to combine a miticide with
the proper insecticide. Sometimes these combinations are
available already mixed for you.

If you wish to control mites without using chemicals,
some satisfaction can be gained by the use of a forceful
spray of water at frequent intervals. Just be sure that you
avoid over-watering the trees when you use this method.
This could lead to other problems.

Dr. J. R. Feucht

VOLUNTEERS NEEDED

One of the many useful services provided by The
Associates is responsibility for the Hospitality Desk which is
set up in the lobby every day and to which hundreds of
visitors head, once inside the door.

Volunteers are being sought for the remainder of the
summer and into the fall. You will be rewarded in many
ways; talking with people from many parts of our own
country, as well as a large number of visitors from abroad;
learning a lot from their questions, as well as supplying some
answers; and most important of all — contributing to the
smooth operation of the Gardens.

If you can spare a few hours each month on a regular
basis, won’t you call Mary Lou Falion (688-9274) who will
be glad to give you more details, or the Denver Botanic
Gardens (297-2547 Ext. 23).

Members will remember that in the spring of this year a
questionnaire was circulated which concerned library usage.

The graduate student who devised the questionnaire asked
“What are the user’s values, attitude and perceptions about
the library, its staff and services? Are the Denver Botanic
members receiving the greatest benefit from present library
facilities and resources?”

Although only 10% of the membership responded, the
results have been tabulated and since they are of general
interest, we are choosing this method of sharing them.

Briefly summarized, the age group that uses the library
most frequently is over 50 years old. The highest usage by
occupation shows homemakers (30.6%) followed by pro¬
fessional people (18.5%) and retired (12.5%).

“Did the fact that you would be able to borrow books
.... have any influence on your decision to become a
member?” No (52.9%), Yes (47.1%).

“If you needed a book on plants . . .,. would you be
more likely to borrow from D.B.G., public library or other
library?” Prefer to use D.B.G. (80%), public library (14.8%),
and other (4.3%).

“How would members feel if non-members had borrowing
privilege?” Unfair to members (58.2%), wouldn’t mind
(37.9%), not sure (3.8%).

(Many qualified this question by suggesting non-members
pay a small fee for borrowing books. A few members
commented that if this policy were adopted they would not
renew their membership.)

Most respondents made very favorable comments about
the library and its service. One hundred seventy-six people
said “yes” when asked if they felt comfortable asking one of
the library staff for help and 59.6% said they received
satisfactory answers “all of the time” to reference questions.

Since space was provided for additional comments, some
people suggested improvements: a copy machine be installed;
books by mail; journals should be circulated; inter-library
loan (Editor: This service is available); a longer borrowing
period; longer hours especially in the evening; have a
smoking section.

The student who drafted the questionnaire and compiled
the responses also made some suggestions for consideration
by the Library Committee. She suggested the library might
consider experimenting with being open one or two nights a
week. (Editor: This was tried last year and met with poor
response.) Volunteers who generally are used on the Circula¬
tion Desk should receive a goodly amount of training in
reference tools and become very familiar with the collection
in order to provide maximum service to library users. The
alternative is to hire an additional professional librarian. New
acquisitions (perhaps with brief annotations) could be
mentioned in the monthly newsletter. This might increase
library usage. (Editor: This is done on an irregular basis as
space permits.)

Again, our thanks to all who participated in this survey.
The formal tabulation is available in the Helen Fowler
Library.

* * * * *

CALLING ALL OVERDUE BOOKS

We’ll welcome back all prodigal books which have overstayed
their leave!

A KINDRED THOUGHT

We’ll welcome, too, prompt payment of overdue fines and
reinbursements for lost books. Both actions will mean more
books on the shelves of the Helen Fowler Library.

Everybody benefits.

A beautiful donation has been received by the Denver
Botanic Gardens in memory of Mr. George Fukuma. His
favorite bonsai, a handsome gnarled juniper, was presented as
the start of the Gardens’ collection. Mrs. Fukuma reports
that Mr. Fukuma collected the tree in the Rocky Mountain
area and that it is thought to be between 450 and 500 years
old. It is displayed in a polished cedar base and is planted in
a black Japanese pot.

This will serve as a living tribute to a fine gentleman.

*****

Did You Know?

The Colorado Cactophiles is an organization of people
who are interested in growing cacti and succulents. One of
their projects is the cactus garden at Red Rocks Park,
located west of the Pueblo and east of the amphitheatre.
Originally in City Park, it was moved to its present site in
1965 and formally dedicated in 1969. All of the specimens
in the garden are Colorado natives.

The Cactophiles meet in the homes of members on the
fourth Sunday of each month. Membership is by invitation.
A prospective member must attend two meetings as a visitor
before becoming eligible. Anyone interested in learning more
about this organization may call the President, Tom Merrick
at 421-8013.

GLADIOLUS SOCIETY SHOW
AUGUST 9 AND 10
1005 YORK STREET

The Hobby Greenhouse Owners Association of America is
aspiring to form a Colorado chapter. An organization
meeting will be held on August 5th at the Community
Room of First Federal Savings and Loan Association, 3460
West 38th Avenue at 7:30 p.m.

All interested people, whether owners of greenhouses or
not, are invited to attend. If you desire further information,
please call Mrs. McNeley, 433-0064.

DENVER BOTANIC GARDENS
CALENDAR OF EVENTS
AUGUST, 1975

AUGUST

1) * 1:00 p.m. Education Building - Horticulture Hall

2) 9:30 a.m. Education Building — Lecture Room “C”

♦ ♦♦♦♦♦♦♦

4) * 7:00 a.m. Botanic Gardens House — Parking Lot

4) 7:30 p.m. Education Building — Horticulture Hall

5) 9:00 a.m.

5) 10:00 a.m.

5) * 10:00 a.m.

5) 7:30 p.m.

6) * 8:30 a.m.

6) 9:00 a.m.

7) * 8:30 a.m.

7) 9:00 a.m.

7) 10:00 a.m.

7) * 7:30 p.m.

8) 7:30 p.m.

9) 9:00 a.m.

Education Building — Horticulture Hall
Education Building — Lecture Room “C”
Education Building — Herbarium
Education Building — Lecture Room “C”
Botanic Gardens House — Main -
Dining & Kitchen

Education Building — Horticulture Hall
Botanic Gardens House — Main -
Dining & Kitchen

Education Building — Horticulture Hall
Education Building — Lecture Room “C”
Education Building — Lecture Room “C”
Botanic Gardens House — Main -
Dining & Kitchen

Education Building — Horticulture Hall

9) 10:00 a.m. Education Building — Lecture Room “B”

9) 1 :30 p.m. Education Building — Lecture Room “C”

10) 9:00 a.m. Education Building — Horticulture Hall

11) 7:30 p.m.

12) 10:00 a.m.

12) * 4:00 p.m.

13) * 8:00 a.m.

♦ ♦♦♦♦♦♦♦

Botanic Gardens House — Main Room
Education Building — Lecture Room “C”
Botanic Gardens House — Dining Room
Meet at 1420 Trenton Street

13) * 7:30 p.m.

14) 10:00 a.m.

14)* 3:30 p.m.

14) 8:00 p.m.

15) 7:30 p.m.

16) * 7:00 a.m.

Botanic Gardens House — Dining Room
Education Building — Lecture Room “C”
Botanic Gardens House — Dining Room
Botanic Gardens House — Main -
Dining & Kitchen
Education Building — Herbarium
Botanic Gardens House — Parking Lot

16) 10:00 a.m. — 5:00 p.m.

Denver 4-H Fair — Dress Review Judging
“Canning & Freezing Garden Produce”

Ms. Jackie Anderson

♦ ♦ ♦ ♦

Field Trip to Mt. Goliath

Instructors: Mrs. Susie Ash & Mrs. Marjorie Shepherd

Colorado Mycological Society

Lecture by: Dr. Alexander Smith

Denver 4-H Fair & Exhibits

Slide Show

Herbarium Committee Meeting
Denver Audubon Society
D.B.G. Guild - (Vinegar Day)

Denver 4-H Fair & Exhibits
D.B.G. Guild — (Vinegar Day)

Denver 4-H Fair & Exhibits
Slide Show

Colorado Open Space Council (Board Meeting)
Denver Dahlia Society

Gladiolus Society Show & Sale
OPEN TO PUBLIC: 1 :00 - 5:00 p.m.

Colorado Organic Growers & Marketers Assn.

Film Series — “New Gardens of Japan”

Gladiolus Society Show & Sale

OPEN TO PUBLIC: 10:00 a.m. - 4:00 p.m.

♦ ♦ ♦ ♦

Sierra Club — (Wildlife Workshop)

Slide Show

Executive Committee

Plants of the City — (Limit: 20)

Instructor: Miss Exie White
Landscape Industry Council
Slide Show

Development & Public Relations Meeting
Denver Rose Society

Denver Botany Club

Field Trip to Florissant Fossil Beds National
Monument

Instructor: Mr. Hank Kanski (Limit: 20)
Photographer’s Day

18)* 9:00 a.m.

♦ ♦♦♦♦♦♦♦

Education Building — Lecture Room “B”

♦ ♦ ♦ ♦

Techniques of Collecting and Drying Flowers
in Silica Gel

Instructor: Mrs. Avalonne Kosanke (Limit: 18)

CALENDAR OF EVENTS FOR AUGUST (Continued)

18) *

Noon

Botanic Gardens House — Dining Room

Colorado Garden Show, Inc.

19)

10:00 a.m.

Education Building — Lecture Room “C”

Slide Show

20)

9:00 a.m.

Botanic Gardens House — Parking Lot

PLANT LIFE FIELD TRIP -
Dr. E. H. Brunquist

20)

7:30 p.m.

Education Building — Horticulture Hall

Congress Park ad hoc Planning Committee

21)

10:00 a.m.

Education Building — Lecture Room “C”

Slide Show

21)

7:30 p.m.

Education Building — Lecture Room “C”

Organic Gardening Club of Denver

22) *

9:00 a.m.

Education Building — Lecture Room “B”

Techniques of Collecting and Drying Flowers
in Silica Gel

Instructor: Mrs. Avalonne Kosanke (Limit: 18)

22) *

10:00 a.m.

Education Building — Horticulture Hall

Ikebana International

23) *

8:00 a.m.

Education Building — Horticulture Hall

♦ ♦♦♦♦♦♦♦

Children’s Garden Fair

♦ ♦ ♦ ♦

26)

10:00 a.m.

Education Building — Lecture Room “C”

Slide Show

26)

7:30 p.m.

Education Building — Lecture Room “C”

Gladiolus Society

27) *

8:30 a.m.

Botanic Gardens House — Main -
Dining & Kitchen

D.B.G. Guild (Vinegar Day)

27)

7:30 p.m.

Education Building — Lecture Room “C”

Colorado Open Space Council (Wilderness Workshop)

28)

8:30 a.m.

Botanic Gardens House — Main -

Dining & Kitchen

D.B.G. Guild (Vinegar Day)

28)

10:00 a.m.

Education Building — Lecture Room “C”

Slide Show

28)

7:30 p.m.

Education Building — Lecture Room “A”

Capitol Hill United Neighborhood

28)

7:30 p.m.

Botanic Gardens House — Main -

Dining & Kitchen

Men’s Garden Club of Denver

30)

9:00 a.m.

Education Building — Horticulture Hall

Denver Dahlia Society Show

OPEN TO PUBLIC: 1 :00 - 5:00 p.m.

30) *

All Day

Botanic Gardens House — Main -
Dining & Kitchen

Denver Dahlia Society —

Breakfast & Luncheon

31)

9:00 a.m.

Education Building — Horticulture Hall

Denver Dahlia Society Show —

OPEN TO PUBLIC: 10:00 a.m. - 4:00 pun.

31)* 10:30 a.m.

SEPTEMBER

Botanic Gardens House — Dining Room

♦ ♦♦♦♦♦♦♦

Denver Dahlia Society

♦ ♦ ♦ ♦

2) *

10:00 a.m.

Education Building — Herbarium

Herbarium Committee Meeting

2) *

1:00 p.m.

Botanic Gardens House — Dining Room

Editorial Committee Meeting

2)

7:30 p.m.

Education Building — Lecture Room “C”

Denver Audubon Society

4) *

7:30 p.m.

Education Building — Lecture Room “C”

Colorado Open Space Council - Board Meeting

4)

7:45 p.m.

Education Building — Horticulture Hall

Denver Orchid Society

5) *

11:00 a.m.

Botanic Gardens House — Main -
Dining & Kitchen

Civic Garden Club, Inc.

6)

9:30 a.m.

Education Building — Lecture Room “A”

Plant Identification for National Jr. Horticulture

6)

9:30 a.m.

Botanic Gardens House — Main Room

Gloxinia Gesneriad Growers

6) *

1:00 p.m.

Education Building — Horticulture Hall

Children’s Garden Graduation

*For members or enrollees only.

August Classes

Canning and Freezing Garden Produce, a free class open
to all, will be taught on Saturday, August 2, at 9:30 a.m.,
Classroom C.

August 4 will be the last scheduled trip to Mt. Goliath
this season. Meet at 7:00 a.m. at 909 York Street, or at
9:00 a.m. at Echo Lake Lodge. Free but limited to 20
participants, please.

Vegetables will be the next area studied by those
interested in the N.J.H.A. program. This will be taught by
Gary Neidercom at the Adams County Fairgrounds near
Henderson, Colorado. Take Highway 85 to 120th and turn
west across the Platte. Free but limited to students under 21
years of age.

Miss Exie White will lead a walk around Denver on
August 13. In this she will point out many of the commonly
seen Plants of the City, both native and exotic, and discuss
some of their interesting characteristics. Meet at 1420
Trenton at 8:00 a.m. Limit 20, no sign ups accepted before
July 30, please.

A day long field trip to Florissant Fossil Beds National
Monument is scheduled for August 16. The naturalist in
charge will show us around this world famous area. The
group will meet at 7:00 a.m. at 909 York or at 10:00 a.m.
at the National Monument Headquarters Building. Take
Colorado 24 west from Colorado Springs for 35 miles to the
town of Florissant, turn left on the Cripple Creek Road for
2 miles to the Headquarters Building. Bring lunch. Free.
Limit 20. No sign ups before July 31, please.

If anyone wishes to learn more, The New Yorker
magazine of November 13, 1971, had a fascinating article
on this area.

Mrs. Robert Kosanke, who is known to all our members
because of her artistic talent and flair, will share some of her
expertise in Techniques of Collecting and Drying Flowers in
Silica Gel. This class is to be taught for two days, August 18
and August 22. Each day the students will meet promptly at
9:00 a.m. in Classroom B. The first day flowers (mostly
large members of Compositae and Rosaceae ) will be
collected from the gardens and on Friday, Mrs. Kosanke will
show how to make arrangements to provide winter color for
the home.

Please bring a plastic shoe box and a gallon plastic
container with a tight lid. Also, please bring scissors or a
sharp knife and wire cutters or pliers that will cut wire.
Wire, tape, Flower Dry and flowers will be provided. The
cost is $10.00 for members and $15.00 for non-members.
Limit 18.

Finally, Dr. Brunquist will take all interested on a Plant
Identification Field Trip on August 20. Meet at 909 York at
9:00 a.m. Free, bring lunch.

“New Gardens of Japan” will be the next free film
on our series. This will be at 1:30 p.m. August 9th,
Classroom C. All welcome.

********

The Denver 4-H Fair will be held in and around 1005
York Street on August 6 and 7. Many exhibits and projects
will be on display in Horticulture Hall. Booths also will be
set up near the amphitheatre and garden produce and baked
items will be on sale along with American and Colorado
Flags.

Thursday evening at 7:00 p.m. a style show featuring
clothes made by 4-H’ers will be held in Horticulture Hall.

Come and see the fine work these young people are
doing.

CAMERA DAY

Shutterbugs should be the only bugs evident at Denver
Botanic Gardens Saturday, August 16, when photographers,
amateur or professional, are invited to capture on film
favorite flowers, landscapes or other subjects at 1005 York
Street.

For budding camera buffs who seek additional expertise
in the use of telephoto lenses, extension tubes, bellows
and/or flash Charles M. Major, prominent exhibitor of nature
photographs, will give a how-to talk on “Close-Up Nature
Photography” at 10 a.m. in Horticulture Hall and with
qualified assistants will offer helpful advice in the Gardens
until noon and from 1 to 3 p.m.

Although visitors may photograph subjects of their choice
at the Gardens throughout the year amateurs are encouraged
to visit on this particular day when flowers should be
colorful and when outstanding nature photographers from
Englewood Camera Club and the Colorado Photographic Arts
Center will offer assistance at various locations in the
Gardens following Mr. Major’s class. Mr. Major has taught at
the Photographic Arts Center where he is a member of its
board of directors, he has juried at Denver International of
Photographic Society of America and he has taught adult
education courses elsewhere as well.

Interested persons may bring a piece of cardboard (about
814” x 11”) and aluminum foil to cover for a quick but
efficient light reflector. Useful tips will be furnished. There
is no charge for the illustrated lecture and, of course,
admission to the Gardens is always free.

NOTED MYCOLOGIST TO TALK
ON WESTERN MUSHROOMS

Alexander H. Smith, eminent mycologist, professor,
Curator and Director of the Herbarium, University of
Michigan, will address the Colorado Mycological Society and
members of the Denver Botanic Gardens on August 4, 7:30
PM., in Horticulture Hall.

The subject of his illustrated talk will be “Rocky
Mountain Mushrooms.” C.M.S. and D.B.G. members will be
admitted free but there will be a $2.00 admission charge for
non-members.

Dr. Smith is a retired Professor of Botany from the
University of Michigan, is Past President of the Mycological
Society of America, the Michigan Academy of Science, Arts
and Letters and the Michigan Botany Club.

He was editor of the national publication Mycologia, and
holds honorary membership in the Mycological Society of
Mexico and the British Society of Mycology. He has been
awarded a lifetime membership in the French Mycological
Society, and the California and Oregon Mycological
Societies.

He is a recipient of the Certificate of Merit from the
Botanical Society of America and Has received the North
American Mycological Society award for “Contributions to
Amateur Mycology”.

Dr. Smith has written 12 volumes and over 100 papers
and journals including “Mushroom Hunters' Field Guide”
and “Mushrooms in Their Native Habitat. ” His most recent
publication is Field Guide to Western Mushrooms.

Everyone welcome.

FOR EVERYONE’S BENEFIT

If you are planning a move, please notify the Denver
Botanic Gardens a month in advance because second class
mail cannot be forwarded. The Post Office will provide a
form, or just send our office a note giving old and new
address and date of change. Thank you.

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Denver Botanic Garden Site
of 1975 A. D. S. National Show

The Denver and Colorado Dahlia Societies after consulting
with Dr. William Gambill on the availability of the Botanic
Garden Auditorium, made a bid for a National Show. We
were awarded the bid which was made three years ago; we
are now working down to final show time. Colorado will be
honored with the 9th American Dahlia Society National
Show, and the Denver Society at the same time will host the
42nd Midwest Conference Dahlia Show. Our two clubs are
not as large in membership as they might be, but we formed
our committees and started to work. We have had problems,
but I suppose no more than other clubs putting on a
National Show.

We have two fine sponsors — The Columbia Savings and
Loan Association and The Denver Botanic Gardens. The
Denver and Colorado Dahlia Societies are the participating
hosts. The Cosmopolitan Hotel will be the show head¬
quarters. All room reservations must be made direct to the
hotel. Arrangements have been made for transportation to
and from the Gardens.

The theme of the show is “MOUNTAIN SPLENDOR”
and we have been promised by Mr. Lee Ashley some
spectacular dahlia arrangements for the show. The show
dates are August 28 through 31 with registration and a
hospitality get together Thursday. A planned tour is
scheduled on Friday with dahlia entries for the show Friday
evening. The Judges’ Breakfast and judging of the show is set
for Saturday, with a dinner banquet at the Cosmopolitan
Hotel Saturday evening. Sunday will schedule important
meetings of interest to dahlia growers at the Botanic
Gardens. Horticulture Hall will be open to the public at 1 :00
p.m. Saturday and all day Sunday from 9:00 a.m. to 5:00
p.m. The Denver Society had a good number of tubers and

pot-roots donated for planting at the Botanic Garden Dahlia
Plot. We had donations from Holland and various growers
throughout the United States. The Dahlia Club finished
separating these roots in preparation for planting this season
in the Botanic Garden and the Garden workmen raised the
dahlia plot for better water drainage. We hope to have some
beautiful dahlia specimens for our visitors to view through¬
out the summer and especially at show time. Our club is
grateful for the fine spirit of cooperation we have received
from the whole staff of the Denver Botanic Gardens.

Our clubs strongly urge all dahlia growers in Denver and
the surrounding area to enter our dahlia show this August.
There are no entry fees — contact any member of the
Denver Society for further information.

We know we grow some of the finest dahlias in the
United States and we would like your help in proving it to
our show visitors. I am sure after viewing this dahlia show
our visitors will long remember “MOUNTAIN SPLENDOR”
in “COLORFUL COLORADO.”

Edward J. Pankoski
Publicity Committee

Dr. William G. Gambill, Jr., Director of the Gardens, was
the awards banquet guest speaker at the 49th Annual
Meeting of the Colorado Federation of Garden Clubs, Inc. at
Estes Park, Colorado.

Following the convention theme, “Blazing Trails for
Progress”, Dr. Gambill detailed the many improvements and
additions at the Denver Botanic Gardens.

Glenn Park, Assistant Director, will discuss the special
problems of growing house plants in the Rocky Mountain
region as part of the Denver Public Library’s Centennial —
Bicentennial program. This program will be held at the
Eugene Field Library from 7:30 to 9:00 p.m. on August
26th.

Green Thumb Newsletter is published monthly by Denver Botanic Gardens,
Inc., 909 York Street, Denver, Colorado 80206. The Newsletter is included as a
benefit of membership in the Denver Botanic Gardens, regular membership dues
being $10.00 a year. Items for publication are welcome. The deadline for copy
to the editor is 2:00 p.m. on the 10th of each month preceding publication.
Editor — Margaret Sikes, 297-2547, Ext. 23.

GreeMhumb Newsletter DENVER botanic gardens, inc.

Copyright 1975

NUMBER 75-9 SEPTEMBER 1975 TELEPHONE 297-2547

GARDENING TIPS FOR SEPTEMBER

Ah, the fall season will be soon arriving. To me, fall is the
best season of all; not just because of the beautiful fall
colors, but quite frankly, I get tired of mowing lawns, trying
to water everything just right, coping with the bugs and
diseases, and trying to “beat the heat.” To me, fall is a time
when we can relax about the garden and do a little dreaming
about next year.

Spring Flowering Bulbs

It is not too early to begin planning your garden for the
spring flowering bulbs such as tulips and daffodils which
should be planted in the fall. Good quality bulbs should be
purchased early or as soon as they are available on the
market. Waiting too long to purchase your bulbs usually
results in an inferior quality with only the picked-over and
badly bruised bulbs left. It is also well to get them into the
ground as soon as they are available so that you are not cut
short like many were last year. I was among them and found
myself planting bulbs during the Christmas holiday. Some
blossoms resulted but they were certainly not as satisfactory
as they would have been had they been planted earlier. The
reason is that when bulbs are planted in the fall, they
immediately develop their root system from the stored food
in the bulbs. If the ground is at or near freezing
temperatures when the bulbs are planted, a good root
development will not occur and this will effect the shoot
growth and the flower formation later on. For best results,
bulbs should be planted in well-drained soils. In Colorado we
recommend planting them deeper than the charts distributed
with the bulbs indicate. If you would like a copy of the
chart adjustment for Colorado conditions, you may write to
the author at 909 York Street, Denver, Colorado 80206, or
call 355-8306.

Fall Planting of Trees and Shrubs

Even though spring is considered the best time to plant or
transplant trees and shrubs, many can be successfully estab¬
lished in the fall provided a little extra care is given. If you
have trees and shrubs in your yard that need to be moved
from one place to another, it is advisable to move them just
as soon as they begin to drop their leaves. Don’t wait until
all the leaves have dropped. The important consideration in
fall planting is that there is sufficient time for re¬
establishment of a root system before the ground freezes.
Plants that do not have a sufficient root system will tend to
dry up in winter. If you plant in the fall, it is a good idea to
apply a mulch, such as wood chips or other insulating
material over the surface of the ground after planting in
order to delay penetration of frost. Such mulches should be
removed in the spring, however, to allow the ground to
warm up; otherwise, it will tend to delay resumption of
growth in the spring. As to the selection of a mulch, most
any organic material will do as long as it does not tend to
compact. Avoid such things as finely pulverized peat or
layers of grass clippings.

Fall Mowing

The question most often asked is, “Should the lawn be
cut shorter in preparation for winter?” This has been a
common practice in order to avoid the matting effect that

may occur during periods of prolonged snow cover. My
question is, “What is short?” If you are mowing your lawn
at the height of 2 to 2 Vi inches, the final mowing could be
reduced to about one and three-fourths inches. Cutting it
shorter than this, I believe, will shock the grass and make it
less apt to survive the winter, particularly if we have an
open, dry winter like last year.

Preparation for Winter

This is the time when the plants in your yard are getting
ready, in fact they have been getting ready for winter for
some time now. As mentioned in our previous issues, you
can help your plants get ready for winter by gradually
withholding water where possible but care should be taken
not to withhold too much to the ultimate detriment of the
plants.

Much has been said about fertility programs in the fall.
Some people do not advise the use of nitrogen fertilizers
because it will tend to produce unwanted growth that could
be subject to frost or freeze damage. This is probably true if
high rates of nitrogen were to be added along with heavy
watering. Most authorities, however, now agree that nitrogen
applied in tire fall at moderate rates is beneficial to plants
and for the most part, will not stimulate new growth.

Most trees and shrubs begin their preparation for winter
because of two very basic circumstances. One is shorter day
length and the other is cooler nights. Linden, Oak, and
Hackberry for example, have already set their winter buds
and are going into the dormancy cycle regulated mostly by
shorter day lengths. This is, for the most part, irreversible.
Such plants rarely, if ever, suffer from freeze injury due to
untimely cold weather. On the other hand, trees like Green
Ash, Golden rain tree, and Soft Maples, will occasionally put
out a late flush of growth, particularly if encouraged by
heavy watering and fertilizer practices. These are the ones
that should be gradually hardened off by withholding or
reducing watering practices. When cooler weather sets in and
plants have slowed down their growth, there is no reason
why trees and shrubs cannot be fertilized in the fall. I prefer
to wait until October, or at least until leaves are beginning
to drop and fall color is showing.

The same is true with the lawn. Blue grass turf responds
best to a nitrogen fertilizer when applied during the cool
season. It is at this time that blue grass tillers, or side
growth, will develop. These tillers help to fill in some of the
open spots in your lawn.

Rodent Control

Many gardeners experience severe damage from field mice,
voles and related rodents this time of year. The greatest
damage seems to be in outlying areas where there are
adjacent fields. During the winter months, the rodents find
blanket covering beneath pfitzers, tammy junipers and
similar evergreens that are dense enough to give them
protection. Unfortunately, the damage that they do isn’t
really too obvious until the spring and summer months. By
then, control is too late. This is another case when an ounce
of prevention is worth a pound of cure. Steps can be taken
to prevent rodent damage. First, make sure that leaves and
other mulch materials are kept away from the base of the

(Continued back page)

SEPTEMBER CLASSES

Many varied classes are to be offered by the Denver
Botanic Gardens starting in September. Although all
members should have received the Fall List of Classes by
now, a reminder might be in order. Don’t delay in signing up
for the class you wish. Many are quite popular and are
limited in size.

Plant Review for those in the National Junior Horti¬
culture Association program will be taught at 9:30 AM,
September 6, Classroom A. This is an especially important
session for the contest is the next Saturday.

Also on September 6, Mr. Novitt, who has displayed
hydroponic units at the Gardens all summer, will discuss
Mineral Water Gardening. This is to be taught at his garden,
5680 E. Cornell Ave. at 9 AM (turn right off Yale at So.
Hudson and go one block to East Cornell). Fee $1.00.

On September 9 join us as we Tour the Governor’s
Mansion and Gardens. Meet at 12:45 at 909 York Street, or
if you wish to try to find a parking space at 8th and Logan,
be there at 1 PM. Limit 20. Please sign up after August
29th. Free.

Two Elementary classes in Bonsai will be offered on
Monday, September 15, 22 and 29th. Sign up either for the
morning one, 10 AM until Noon, or the evening at 7:30 to
9:30 PM. The cost is $10.00 for members, $15.00 for
non-members. Limit 15 in each class.

This is to be followed by Intermediate Bonsai on the
Mondays in October with the same choice of morning or
evening hours.

On the last Plant Identification Field Trip this season, we
may see:

“Thou blossom bright with autumn dew,
and colored with the heaven’s own blue . . .

(The Fringed Gentian by William Cullen Bryant)

Meet at 909 York on September 17 at 9 AM. Bring lunch.
Free.

The Guides will soon resume their regular program of
tours again. So that they may leam the new plants in the
Conservatory, Mrs. Hayward has planned two brush-up
sessions on September 17 and 24; meet at 1 PM at the
entrance to the Conservatory.

Also on the 17th, staff member Larry Latta will begin a
six week course in Vegetable Gardening. No doubt many
members had productive gardens this summer, but basic
information on site selection, soil preparation and related
matters is always useful. Meet at 10 AM in Classroom A.
The fee is $10.00 for members and $15.00 for non-members.

The Chrysanthemum is considered by many the flower of
fall. Come on September 20 at 9 AM, Classroom C, when
Ray Blue of the Men’s Garden Club will explain culture and
care of this beautiful plant. Free.

Those of you who have visited the Gardens in summer
know that much work has been done. New plantings in the
outside gardens at the Denver Botanic Gardens in 1975 total
71 different varieties of plants. Have you seen these:

Abies concolor
Acer ginnala

Acer platanoides ‘ Emerald Queen ’

Amelanchier grandiflora

Aronia arbutifolia var. Brilliantissima

Betula nigra

Cercis canadensis

Cercis canadensis Forest Pansy ’

Comus baileyi

Cornus stolonifera ‘ Kelsey i’

Corylus avellana var. con tor ta
Cotoneaster acuti folia
Co tone aster apiculata
Cotoneaster divaricata
Euonymus alata
Euonymus alata var. compacta
Forsythia Farr and Hybrid’

Gleditsia triacanthas var. inermis ‘Imperial’

Juglans regia ‘Carpathian ’

Juniperus chinensis ‘ Armstrong ’

Juniperus chinensis ‘ Blaauw ’

Juniperus chinensis ‘Hetzi’

Juniperus chinensis ‘Procumbens’

Juniperus sabina ‘Arcadia’

Juniperus sabina ‘Blue Danube ’

Juniperus sabina ‘ Broadmoor ’

Juniperus sabina ‘Buffalo’

Juniperus sabina \ Scandia ’

Mahonia aquifolium ‘Compactum ’

Malus ioensis ‘Prairie Rose ’

Malus zumi var. calocarpa
Picea pungens

Picea pungens var. glauca ‘Thompson ’

Finns aristata
Pinus cembra

Pinus cembroides var. edulis
Pinus flexilis var. reflexa
Pinus flexilis \ Silver ’

Pinus mugo
Pinus strobus

Pinus strobus var. fastigiata
Pinus sylvestris var. fastigiata
Potentilla ‘Katherine Dykes’

Prunus cistena

Pyracantha angustifolia ‘Gnome’

Quercus macrocarpa
Quercus palustris
Quercus borealis
Rhamnus frangula ‘Tall Hedge’

Rhus aromatic a

Rhus aromatica ‘Green Globe ’

Rhus typhina var. laciniata
Rosa ‘Austrian Copper’

Sorbus aucuparia

Spiraea nipponica ‘Snow Mound’

Syringa amurensis var. japonica
Syringa meyeri
Viburnum X carlcephlum
Viburnum carlesii
Viburnum dentatum
Viburnum dilatatum
Viburnum lan tana var. rugosum
Viburnum trilobum
Viburnum trilobum ‘ Hahs ’

Weigela ‘ Vanicek ’

Yucca filamentosa

Our Assistant Director, Glenn Park, who has been directly
involved in all of the planning and planting, will take those
interested on a leisurely Tour of the Outside Gardens. Meet
at 909 York Street at 9 AM on September 23. Free.

Dr. Zeiner will teach How to Force Bulbs for Indoor
Bloom on September 27, 9 AM, Classroom B. Free.

And finally on the same day, Dr. Gambill will lead a Tree
Walk in Washington Park. Meet at 1 PM at 909 York Street
or 1:20 PM at 1300 E. Virginia Ave. Free.

Five classes in Rose Culture will be offered by the
Community College of Denver at the Denver Botanic
Gardens. Mr. Ross Lahr, well known rosarian, will teach
these from October 15 through November 12 from 7:30 to
9 PM. Such topics as soil preparation, bed location and
planting through pruning and winter care will be discussed.
For further information, call Sara Collier at 266-1881.

The September movie will feature a Disney Production,
“One Day at Teton Marsh,” based on the book by Sally
Carrighar. This is to be shown on September 13 at 1:30 PM.
Classroom C. Free.

The Botany Club is willing to help identify slides of

Colorado wild flowers. Their regular meeting is the third

Friday of each month. Contact Marjorie Shepherd

733-8229 for further information. _

Visitors to the Helen Fowler Library, have been admiring
the handsome bulletin board displays. These feature a
current flower or garden topic and are set off with appro¬
priate books. Our thanks go to Nancy Jackson for all her
work.

Children’s Garden Graduation will be held on September
6 at 1 PM in Horticulture Hall. Certificates will be awarded
to all the children who have successfully completed the
program and prizes will be presented to the winners of the
best gardens. Refreshments will be served and all are invited
to tour the Children’s Garden across the street after the
program.

OAK TREES HONORING TWO D.B.G. FRIENDS

A group of ten oak trees has been planted in the Gardens
in honor of Mrs. William H. (Katharine B.) Crisp and the late
Mr. Edward Mixa. Some twenty friends of Mrs. Crisp, the
Associates of D.B.G. , and Around the Seasons Club joined in
contributing funds for the trees planted in tribute to Mrs.
Crisp for her long service to the Gardens, particularly on the
Editorial Committee.

The Edward Mixa trees were made possible by a gift from
Mrs. Mixa and her son, Edward. Mr. Mixa had done much
handicraft work for the Gift Shop and other projects.

There are four Red Oak, three Pin Oak and three Bur
Oak trees in the group, ranging from six to twenty feet in
height, and located just east and south of the Home
Gardeners Workshop Demonstration Area near the center of
the Gardens.

********

A handsome new shadow box for the edification of our
many visitors, especially those on tours, has been placed in
the Education Building. This displays tropical seeds like
mango, kapok and pandanus, along with an informative
label.

Thanks to guides Judy Moore, Peg Hayward and Helen
Bergkamp for all their work, and to Harold Bergkamp for
the construction of the shadow box and easel.

********

It’s Thrift Shop Time Again!

The University Thrift Shop, 600 Ogden Street, gives
proceeds from sales of donated clothing and other items to
numerous civic organizations, including the Denver Botanic
Gardens. Items for sale may be taken to the Shop during
store hours, 9 AM to 4 PM, Monday through Saturday. Our
next benefit week is September 29 through October 4. Your
help is appreciated.

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GARDENING TIPS (Continued)

shrubs. One can also resort to use of various live traps
available from farmer’s feed and supply stores. This method,
however, requires a lot more time and maintenance than
many people like to expend.

Another good preventative method is the use of various
rodent poisons that are available. Since these are very toxic
materials, they should be used with care, particularly, so that
they do not come in contact with children, birds, or
household pets. One of the best methods is to take lengths
of black polyethylene pipe about one inch in diameter and
about 12 - 18” long; place the rodent poison towards the
middle of the pipe making it inaccessible to only very small
animals such as mice. These traps can then be placed
beneath the shrubs out of sight and relatively safe from
discovery by children. Most of the effective qualities of most
poisons are lost in time so it will be necessary to renew the
poisons two or three times during the winter months. As
cautioned in last month’s column, use these poisons with
utmost care, follow the directions on the label and be sure
that the poisons are stored in a location not accessible to
children.

Dr. J. R. Feucht

It’s that time again when people bring mushrooms to
identify. It will help the members of the Mycology Club
if you will remember these tips from Spores Afield.

Bring fresh specimens wrapped in wax paper, not
air-tight.

Bring a spore print on WHITE paper.

Try to identify your own mushroom.

Write a gross description of the fungus, its size, place
found, growing habitat, altitude — and include
your name.

IX) NOT — bring frozen specimens.

DO NOT — wrap in plastic or plastic bag; it makes
them sweat and unusable.

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IKEBANA DEMONSTRATION AT THE GARDENS

The local chapter of Ikebana International will hold a
demonstration in Horticulture Hall on Friday, September 26,
at 2 PM. It will be conducted by Miss Tasumi Tshigahara,
Grand Master of the Sogetsu School in Tokyo. Tickets may
be obtained for a $6 donation. On Saturday, September 27,
there will be an all-day Ikebana workshop, 10 to 12, and
1:30 to 3:30, also conducted by Miss Tshigahara. Donations
for that day are $5 each session or $4 each session to
observe. Information and reservations can be obtained by
calling Mrs. Ray Light, 860 Inca Place, Boulder 80302,
499-9606. Also, all members will have tickets for sale.

Green Thumb Newsletter is published monthly by Denver Botanic Gardens,
Inc., 909 York Street, Denver, Colorado 80206. The Newsletter is included as a
benefit of membership in the Denver Botanic Gardens, regular membership dues
being $10.00 a year. Items for publication are welcome. The deadline for copy
to the editor is 2:00 p.m. on the 10th of each month preceding publication.
Editor — Margaret Sikes, 297-2547, Ext. 23.

GreCJ} Thumb Newsletter DENVER BOTANIC GARDENS, INC.

Copyright 1975

NUMBER 75-10 OCTOBER 1975 TELEPHONE 297-2547

GARDENING TIPS FOR OCTOBER

This is probably as good a time" as any to reflect on the
past growing season. Whether we have a killing frost or not,
the growing season is over and all of our trees and shrubs are
hopefully well into the hardening-off stage so that they can
take whatever mother nature cares to dish out.

A few years ago, this column reflected back on the
growing season and called it “The Year of the Bugs”. This
has been a year we can call “The Year of Diseases.” As a
matter of interest, records kept in this office show that
requests for assistance with diseases during the month of
July were 42% above a five-year average and 40% above the
average for the month of August. Normally, insects are the
big problem during these months but the climatic conditions
seem to promote more diseases such as Fire Blight in fruit
trees.

Fire Blight Severe

Unless you have a resistant strain of apple tree such as
Red Delicious, you probably have experienced Fire Blight.
This leads to the question, “What can I do with blighted
trees”? Unfortunately, there are no effective control
measures, at least of a chemical nature. The Agrimycin and
Streptomycin sprays frequently recommended are really only
effective when applied during the blossom stage in early
spring. Even then they are at best, only a partial control.
Fire Blight is a bacterial disease and is systemic in nature;
that is, it travels throughout the system of the plant itself.

There are various stages of blight conditions. The first is
blossom blight, followed by twig blight; the most common
seen this year, and fruit blight which results in shriveling and
mummifying of the fruit. The most serious of all is the
so-called hold-over canker. The latter usually shows up as a
discoloration of the main trunk of the tree.

Fire Blight can be pruned out during the blossom, fruit
and twig stages. When pruning, use sterile techniques,
dipping the pruning shears in alcohol between cuts or, more
conveniently, spraying them with household lysol. Always
make the cut about 12” back on any blighted twig to be
sure that you are removing the entire diseased area.

Slow Season for Vegetables

This has been a strange growing season for vegetables.
You have undoubtedly discovered by now that cold-season
crops such as cabbage, lettuce and broccoli and root
vegetables like beets and carrots have performed very well, at
least until the heat hit in the latter part of the summer. You
may have also noticed, however, the tomatoes were very late
in ripening, beans were not up to snuff compared to last
year and some varieties of squash simply refused to be
productive. This was, in fact, a very late year, thanks to a
very cold spring and particularly an unseasonably cold June.
In fact, I was beginning to think that summer would never
get here. This goes to show us how various vegetable crops
are dependent on temperatures. Tomatoes, for instance will
fail to set well until night time temperatures are above 50
degrees regardless of daytime temperatures. The same is
generally true of other warm-season vegetables such as
peppers and cucumbers. During the rainy season, squash

sometimes developed into a rather strange shape, or in many
cases, failed to develop fruit at all, aborting a few days after
the blossom opened. As much as we need rain, at times it
can have an adverse effect by hindering effective pollination
in certain plants. At times during the rainy season I was
tempted to run out with an umbrella to protect the plants
so that I could be sure of proper pollination. Then I
remembered that it would only be a few days before the
weather would change, as we all know it does in Colorado,
and I’d be back in production again. It seems my garden
went from almost no production of squash to an over¬
abundance and then my problem became how to get rid of
them when the neighbors hate squash. Oh well, this is what
makes gardening fun and different. No two years are alike
and it gives us something to talk about during the long
winter period.

Spring Bulbs

October is a good time to purchase and plant your spring
flowering bulbs. To be sure that you will have a showy
spring bulb garden, pay close attention now to your soil,
particularly, the drainage. Where soils are heavy, the quality
of the flowers will decrease, especially if you intend to leave
them in for more than one year. In very heavy soils the
bulbs often rot before they have a chance to emerge in
spring. By good drainage, I mean a soil, even if it is on a
slope, which has permeability and allows water to penetrate
into the subsoil.

When spring bulbs are planted in the fall, the first thing
that the bulbs do is develop roots. This is often
accomplished within a few weeks after planting. The type of
soil will also dictate how deep bulbs should be planted. Most
planting charts obtained when you purchase your bulbs are
based upon a well-drained soil in eastern United States. In
Colorado it is better to plant them 2” deeper, but only
providing that the soil is well drained and aerated. If the soil
is heavy and you insist on planting the bulbs without soil
improvement, count on them for only one year and plant
them even more shallow than the charts indicate. Shallow
planting will promote splitting of the bulbs and this will
reduce the number of years the bulbs will produce flowers.

Buy Bulbs Carefully

Care should be taken in the purchase of bulbs. Look for
the largest and healthiest ones. Check carefully for
mechanical injuries or signs of mold or mildew and destroy
any with these problems. It is better to pay a little more for
healthy and well-cared for bulbs than paying a cheaper price
for bulbs that will result in a very poor flower garden next
spring. Be wary of the way bulbs are advertised. Many
imported bulbs are measured in centimeters and many local
dealers advertise them giving measurements in inches. A bulb
that is advertised as having a size of 2.5 centimeters may
sound large but if you know your metric system, you will
know that that is the equivalent of 1 inch.

Fall Soil Preparation

This column has not really given too many gardening tips
but maybe it’s because I am getting tired of gardening and

(Continued on back page)

CHRISTMAS SALE

Around the Seasons is getting ready for the Christmas
Sale (November 21 and 22) and needs help. Does anyone
have money plant, love-in-the-mist, statice, golden yarrow,
teasel or allium? Also needed are acoms, cones, buckeyes,
and sweet gum balls. Other interesting types of dried
materials will certainly be appreciated and put to good use.
Please bring such items to the Botanic Gardens House, 909
York, by October 15th. For further information call
297-2547 or Jane Middlebrook at 789-2887.

Another good reason to visit the Sale is to see the
fascinating array of treasures available there. Besides
calendars, jewelry, note cards and pottery, there are also
many books and pamphlets.

The horticultural side of Denver history, told by the man
who made much of that history, is fascinating reading for
those interested in our plants, parks and city planning. The
gift shop offers two such publications written by S. R.
DeBoer, famous landscape architect and city planner.

Around the Seasons in Denver Parks and Gardens is a
delightfully human and informative account of the unfolding
seasons. It is illustrated by the unusual and lovely drawings
of Francis White Novitt. (A limited number of copies are
still available.)

Plans, Parks and People, Mr. DeBoer’s autobiography,
published in the December 1972 issue of The Green Thumb,
concentrates on the building of the city’s parks and park¬
ways in the early years of this century. Dozens of seldom
seen, old-time photos and drawings add to its rich account.
Here is a part of our history not found in other books.

October Classes

School buses will soon be lined up in front of the
Gardens for the busy season is upon us! Children may depart
from their tour filled with enthusiasm from the experience
and the plants they have seen. Much of course depends on
the teachers and the preparation they have given the classes.
Also much depends on the volunteer guides. You can help.
If you enjoy plants and people, sign up for Tropical Plants
of the Conservatory, Wednesday, October 1, through
November 19 from 1 to 3 p.m. The cost is $25.00 which is
refunded if the student guides for a total of 40 hours.
Limited to 25 students.

Gardening Under Lights, a half day class, will serve as an
introduction to this fascinating hobby. Some topics may be
types of fixtures, quality and quantity of light, and
suggested easy plants to try. Meet at 9 a.m., October 4, in
Classroom C. Free.

The African Violet Workshop, a very popular annual
event, is scheduled this year on October 18 in Horticulture
Hall. The Hi-Hopes Study Club tries to provide as much
individual instruction as possible by having various demon¬
strations throughout the morning. Come at 9 a.m. or later as
you wish. Fee 50<t payable at the door.

The Colorado Federation of Garden Clubs, Inc., is
pleased to announce a series of lectures which are
planned from October to April.

These, designed to be of general interest, will be
offered at the Headquarters Building, 1556 Emerson,
and will cost fifty cents for members of the Federation
and $1.00 for non-members.

On October 22 from 9:30 - 12:30 the schedule
shows “Forcing Spring Bulbs” by Herb Gundell and
“House Plant Care” by Gary Neidercorn. Register at
the door.

The Annual Meeting of the Associates is scheduled for
October 21 in Horticulture Hall.

Our speaker at the Associates Annual Meeting will be
Charles Marden Fitch. Mr. Fitch is a well known author who
has contributed illustrated articles to The New York Times,
Americas, Bon Voyage, the American Orchid Scoiety
Bulletin, Horticulture, Flower and Garden, and other
publications.

As a television director and producer for the Peace Corps
of the United States Department of State and a
Communication Consultant for the Organization of American
States, he lived for several years in the tropics, where he
studied, photographed, collected and cultivated hundreds of
plants.

He is a member of the Garden Writers Association of
America, a Fellow of the Royal Horticultural Society, and
the recipient of several national awards for his work in
conservation.

His most recent book is Complete Book of House Plants
Under Light.

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Photo by Christopher Quinn

Dr. William G. Gambill, Jr., Director of the Denver
Botanic Gardens, has recently returned from Washington,
D.C., where he attended a meeting of the American Horti¬
cultural Society’s Commission on Plant Science Data Center.

This is a significant commission which attempts to keep
track of the ornamental plants of North America by a
computerized record keeping system which is based on
reports of plant material from major Botanic Gardens and
Arboreta. This effort is especially important as more and
more plants are threatened with extinction, for as S. Dillon
Ripley of the Smithsonian reminds us: “All animals are
dependent on plants for food and survival. A diversity of
plant species is required to supply human necessities and to
maintain an ecological stability in the biosphere.”

Dr. Gambill also attended the Thirtieth Annual Congress
of the American Horticultural Society which met this year in
Honolulu. Several sessions focused on plant propagation,
tropical plant cultivation and acclimatization, and tropical
plant materials. Tours to private gardens showed beautifully
landscaped areas and Lyon Arboretum, Foster Gardens and
the Alice Spaulding Home were also visited.

DENVER BOTANIC GARDENS
CALENDAR OF EVENTS
OCTOBER, 1975

OCTOBER

1)*

10:00

a.m.

Education Building — Lecture Room “A”

Vegetable Gardening — Mr. Larry Latta

1)*

1:00

p.m.

Education Building — Lecture Room “A”

Tropical Plants of the Conservatory — Mrs. P. Hayward

1)

7:30

p.m.

Education Building — Lecture Room “A”

Plan Metro Denver

2)*

7:30

p.m.

Education Building — Lecture Room “C”

Colorado Open Space Council — Board Meeting

2)

7:45

p.m.

Education Building — Horticulture Hall

Denver Orchid Society

3)

Noon

Education Building — Horticulture Hall

Civic Garden Club Tea & Heritage Costume Show

4)

9:00

a.m.

Education Building — Lecture Room “C”

Gardening Under Lights — Mr. Dave Woodward

4)

9:30

a.m.

Botanic Gardens House — Main Room

Gloxinia Gesneriad Growers

♦ ♦♦♦♦♦♦♦

♦ ♦ ♦ ♦

6)*

10:00

a.m.

Education Building — Lecture Room “B”

Intermediate Bonsai — Mrs. Mary Neil

6)*

7:30

p.m.

Education Building — Lecture Room “B”

Intermediate Bonsai — Mrs. Mary Neil

6)

7:30

p.m.

Education Building — Lecture Room “C”

Colorado Open Space Council (Wilderness Workshop)

7)*

10:00

a.m.

Education Building — Herbarium

Herbarium Committee Meeting

7)

7:30

p.m.

Education Building — Lecture Room “B”

Denver Bonsai Club

7)

7:30

p.m.

Education Building — Lecture Room' “C”

Denver Audubon Society — Wildlife Workshop

8)*

9:15

a.m.

Botanic Gardens House —

Main - Dining & Kitchen

D.B.G. Guild

8)*

10:00

a.m.

Education Building — Lecture Room “A”

Vegetable Gardening — Mr. Larry Latta

8)*

1:00

p.m.

Education Building — Lecture Room “A”

Tropical Plants of the Conservatory — Mrs. P. Hayward

8)*

7:30

p.m.

Botanic Gardens House — Dining Room

Landscape Industry Council

9)*

3:30

p.m.

Botanic Gardens House — Dining Room

Development & Public Relations Meeting

9)

8:00

p.m.

Botanic Gardens House —

Main - Dining & Kitchen

Denver Rose Society

10)

7:30

p.m.

Botanic Gardens House —

Main - Dining & Kitchen

Denver Dahlia Society

11)

10:00

a.m.

Education Building — Lecture Room “B”

Colorado Organic Grower’s & Marketer’s Association

11)

1:30

p.m.

Education Building — Lecture Room “C”

“The Green City” FREE FILM

♦ ♦♦♦♦♦♦♦

♦ ♦ ♦ ♦

13)*

10:00

a.m.

Education Building — Lecture Room “B”

Intermediate Bonsai — Mrs. Mary Neil

13)

7:30

p.m.

Education Building — Horticulture Hall

Colorado Mycological Society

13)*

7:30

p.m.

Education Building — Lecture Room “B”

Intermediate Bonsai — Mrs. Mary Neil

13)

7:30

p.m.

Education Building — Lecture Room “C”

Colorado Open Space Council (Wilderness Workshop-

13)

7:30

p.m.

Botanic Gardens House — Main Room

Sierra Club — Wildlife Workshop

14)

9:30

a.m.

Education Building — Lecture Room “B”

Civic Garden Club

14)*

4:00

p.m.

Botanic Gardens House — Dining Room

Executive Committee Meeting

15)*

9:30

a.m.

Botanic Gardens House — Dining Room

Around the Seasons (Workshop)

15)*

10:00

a.m.

Education Building — Lecture Room “A”

Vegetable Gardening — Mr. Larry Latta

15)*

1:00

p.m.

Education Building — Lecture Room “A”

Tropical Plants of the Conservatory — Mrs. P. Hayward

15)*

7:30

p.m.

Education Building — Lecture Room “C”

“Rose Culture” — Mr. Ross Lahr

(For information call: Sara Collier — 266-1881)

16)*

6:30

p.m.

Education Building — Horticulture Hall

American Iris Society — Catered Dinner

16)

7:30

p.m.

Education Building — Lecture Room “C”

Organic Gardening Club of Denver

17)

7:30

p.m.

Education Building — Lecture Room “B”

Colorado Bonsai Club

17)

7:30

p.m.

Education Building — Lecture Room “C”

Denver Botany Club

18)

All Day

Education Building — Horticulture Hall

Hi Hopes Study Club — African Violet Workshop

18)*

9:00 a.m.

Botanic Gardens House

International Union of Directors of Zoological Gardens

Main - Dining & Kitchen

Catered luncheon and tour of gardens

CALENDAR OF EVENTS FOR OCTOBER (Continued)

OCTOBER

*

o

C-l

10:00 a.m.

Education Building — Lecture Room “B”

Intermediate Bonsai — Mrs. Mary Neil

20)

12 noon

Botanic Gardens House — Dining Room

Colo. Garden Show, Inc.

20)*

7:30 p.m.

Education Building — Lecture Room “B”

Intermediate Bonsai — Mrs. Mary Neil

20)

7:30 p.m.

Education Building — Lecture Room “C”

Colorado' Open Space Council - Wilderness Workshop

21)*

10:00 a.m.

Education Building — Horticulture Hall

Associates Annual Meeting & Luncheon

21)

7:30 p.m.

Education Building — Horticulture Hall

Sierra Club

22)*

10:00 a.m.

Education Building — Lecture Room “A”

Vegetable Gardening - Mr. Larry Latta

22)*

1 :00 p.m.

Education Building — Lecture Room “A”

Tropical Plants of the Conservatory — Mrs. P. Hayward

22)*

7:30 p.m.

Education Building — Lecture Room “C”

“Rose Culture” — Mr. Ross Lahr

(For infonnation call: Sara Collier — 266-1881)

23)

7:30 p.m.

Botanic Gardens House —

Main - Dining & Kitchen

Men’s Garden Club of Denver

24)*

10:00 a.m.

Education Building — Horticulture Hall

Ikebana International

♦ ♦♦♦♦♦♦♦

♦ ♦ ♦ ♦

27)*

10:00 a.m.

Education Building — Lecture Room “B”

Intermediate Bonsai — Mrs. Mary Neil

27)*

7:30 p.m.

Education Building — Lecture Room “B”

Intermediate Bonsai — Mrs. Mary Neil

27)

7:30 p.m.

Education Building — Lecture Room “C”

Colorado Open Space Council - Wilderness Workshop

28)*

7:00 p.m.

Education Building — Lecture Room “B”

Corps of Engineers - Committee Meeting

28)

7:30 p.m.

Education Building — Lecture Room “C”

Gladiolus Society

29)*

1 :00 p.m.

Education Building — Lecture Room “A”

Tropical Plants of the Conservatory - Mrs. P. Hayward

29)*

7 :30 p.m.

Education Building — Lecture Room “C”

“Rose Culture” — Mr. Ross Lahr

29)

7:30 p.m.

Education Building — Lecture Room “B”

Colorado Open Space Council - wilderness Workshop

31)*

10:00 a.m.

Education Building — Horticulture Hall

Ikebana International Workshop

♦ ♦♦♦♦♦♦♦

♦ ♦ ♦ ♦

NOVEMBER

1)

9:30 a.m.

Botanic Gardens House — Main Room

Gloxinia Gesneriad Growers

3)*

10:00 a.m.

Education Building — Lecture Room “A”

House Plants for the Amateur — Dave Lankhorst

4)*

10:00 a.m.

Education Building — Herbarium

Herbarium Committee Meeting

4)*

1:00 p.m.

Botanic Gardens House — Dining Room

Editorial Committee Meeting

4)

7:30 p.m.

Education Building — Lecture Room “B”

Denver Bonsai Club

4)

7:30 p.m.

Education Building — Lecture Room “C”

Denver Audubon Society

5)

9:00 a.m.

Education Building - Horticulture Hall

International Institute of Education

5)*

10:00 a.m.

Education Building — Lecture Room “A”

House Plants for the Amateur — Dr. Helen Zeiner

5)*

1 :00 p.m.

Education Building — Lecture Room “A”

Tropical Plants of the Conservatory — Mrs. P. Hayward

5)*

7:30 p.m.

Education Building — Lecture Room “C”

“Rose Culture” — Mr. Ross Lahr

6)*

7:30 p.m.

Education Building — Lecture Room “C”

Colorado Open Space Council - Board Meeting

6)

7:45 p.m.

Education Building — Horticulture Hall

Denver Orchid Society

7)*

1 1 :00 a.m.

Botanic Gardens House —

Main - Dining & Kitchen

Civic Garden Club, Inc.

8)

10:00 a.m.

Education Building — Lecture Room “B”

Colorado Organic Grower’s & Marketer’s Association

9)

1 :30 p.m.

Education Building — Lecture Room “C”

FREE FILM

*For members or enrollees only.

This fine editorial from the Denver Post reinforced the
information about endangered species published in the
February newsletter.

PROTECT THOSE PLANTS

Colorado, with thousands of beautiful wild flowers and
plants in the high country, faces a new threat. It is “plant-
naping.”

Encouraged by the boom in house and garden plants,
thieves are making off with trees, shrubs, potted ornamentals
and flowers from wilderness areas, homes, offices, public
highways and city parks.

The Smithsonian Institution, in accordance with the En¬
dangered Species Act of 1973, has drawn up a list of
threatened species of higher plants native to the United States.
The Smithsonian concludes that 10 percent of the some
20,000 species of native higher plants are in danger of
extinction.

“When a plant species is extinguished”, the Smithsonian
magazine warns “ . . its gene pool cannot be duplicated or
reestablished and is lost forever. Each kind that we destroy
narrows our options. Imagine the loss to mankind if we had
destroyed the cinchona before discovering quinine’s anti-
malarial qualities”.

The Smithsonian warning is timely, especially for Colorado
with its numerous state parks, national forests and recreation
and wilderness areas.

The penalties for theft of plants from public or private
property can be severe. But a solution to the problem may be
in formation of a Society for the Prevention of Cruelty to
Plants. They could use the protection.

For further information on this timely subject, please
see National Parks and Conservation and American Forests
magazines, both of April 1975 and the A.A.B.G.A. Bulletin
of January 1975 and the report of their Committee on
Endangered Species.

The following is a list for Colorado of the Endangered
and Threatened Species as reported by The Smithsonian.

ENDANGERED

FAMILY

Apiaceae
Aster aceae
Aster aceae
Boraginaceae
Brassicaceae
Brassicaceae
Brassicaceae
Brassicaceae
Cactaceae
Caryophyllaceae
Fabaceae
Fabaceae
Fabaceae
Fabaceae
Fabaceae
Fabaceae
Fabaceae
Fabaceae
Fabaceae
Hydrophyllaceae
Onagraceae
Polygonaceae
Ranunculaceae
THREATENED
Boraginaceae
Boraginaceae
Boraginaceae
Brassicaceae
Brassicaceae
Brassicaceae
Brassicaceae

SPECIES

Neoparry a lithophila

Haplopappus fremontii ssp. monocephalus

Senecio ported

Cry p tan t ha weberi

Arab is oxylobula

Brava humilis ssp. ventosa

Eutrema penlandii

Lesquerella pruinosa

Sclerocactus glaucus

Stellaria irrigua

Astragalus deterior

A stragalus detritalis

Astragalus lutosus

Astragalus micro cymbus

Astragalus natuntensis

Astragalus osterhoutii

Astragalus sc h mol la e

Oxytropis obnapiformis

Trifolium lemmonii

Phacelia formosula

Gaura neomexicana ssp. coloradensis

Eriogonum ephedroides

Aquilegia micrantha var. mancosana

Cryptantha elata
Cryptantha stricta '

Mertensia viridis var. cana
Arabis gunnisoniana
Draba exunguiculata
Parry a nudicaulis
Rodppa coloradensis

Cactaceae
Cy per aceae
Fabaceae
Fumariaceae
Poaceae
Polygonaceae
Polygonaceae
Polygonaceae
Ranunculaceae
Saxifragaceae
Finally, can you
Gardener of August,
England’s endangered

Sclerocactus mesae-verdae
Carex microptera var. crassinervia
Astragalus wetherillii
Corydalis caseana ssp. caseana
Phippsia algida
Eriogonum brandegei
Enogonum saurinum
Eriogonum vindulum
Aquilegia chrysantha var. rydbergii
Sullivantia purpusii
believe that according to The Avant
1974 the dandelion has been placed on
wildflower list!

“The Green City,” a twenty-five minute film which has
won an International Film Award will be shown on October
11 at 1:30, Classroom C. The subject is the preservation of
open spaces in cities, acquisition of park land, modern
methods of subdivision development and conservation of
nature by builders and city officials. Free. All welcome.

Brrrrrr!

As many of you may
have noticed, the Pygmy
Date Palms that spent the
summer on tire balcony
of the Education
Building, have been
brought back inside. If
any of your house plants
are still out, it is time to
bring them in.

Introducing ....

Lee Schwade has joined the Staff of the Denver Botanic
Gardens as a Botanist-Horticulturist. Lee’s position will
involve work with ornamental plantings, responsibility in the
Children’s Gardens, and in the Chatfield Arboretum. His
education has equipped him for this wide variety of respon¬
sibility for he holds a BA degree from Regis, taught biology
for five years at the high school level, was awarded a
National Science Foundation Grant to the University of
Georgia, completed his MA. at the University of Northern
Colorado and has started his doctoral program at Colorado
State University in Biological Nutrition. All this plus work at
the Community College in Urban Horticulture!

Lee is looking forward to working with the expanding
programs at the Gardens and we welcome him here.

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“Orchids in the Rockies” is the show theme for the
Annual Meeting of the American Orchid Society. This
national meeting is to be held at the Regency Hotel, 3900
Elati, from October 8 through 12th. The show will be open
to the public at 10 a.m. on October 10 and continue until 3
p.m. on October 12.

For further information on any aspects of this
convention, please call Mr. S. L. Stewart, 355-5831.

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GARDENING TIPS (Continued)

looking forward to sitting back and relaxing for a while.
That’s why I think there is a real advantage to living in an
area of so many varied seasons.

At the same time, however, there are things that must be
done in the garden such as cleaning up debris after a hard
frost and improving conditions for next spring. Fall is the
best time to do this by plowing in your well-rotted compost
and other organic material. I like to leave the ground rough
and lumpy to allow better air penetration. Freezing and
thawing during the winter will break down the clods and
leave you with a mellow garden in spring without doing so
much work.

Last year I experimented with an idea that’s not really
new. It’s what I call “composting in place”. Rather than put
the debris on the garden, I windrow it along the edge of the
garden and run over it with a rotary mower repeatedly until
it is all ground up. By moving the mower back and forth
over the material with the shoot pointed to the garden, it
automatically spreads the material over the surface of the
garden, then it can be plowed in. Not all of the debris is
decomposed during the fall and little if any decomposition
occurs in winter, but the presence of the roughage in the top
few inches of the soil helps to keep it open and allows for
good air penetration.

Something to be avoided, however, are weeds that have
gone to seed and certain garden annuals like alyssum, that
do become weeds themselves from the volunteers in spring.
To some extent, you can plan your garden to. reduce the
number of volunteers by using triploid varieties. Many
varieties on the market today are triploid and they produce
few, if any viable seeds.

When all your garden chores are Fmished this fall, you can
sit back and relax, dreaming about your garden for next
year.

Dr. J. R. Feucht

90208. OdVdOlOO ‘U3AN30 • 133H1S >1H0A 606

ONI SN3QUVD 0INV1O9 H3AN3Q

FALL CLEANING? Don’t dust all those books you don’t
read or use. Bring them to the library for the annual book
sale. They’ll gather no dust there!

New library accessions are now being displayed on the
southern portion of the first north-south stack. Most of
these books are new but some may be older volumes which
are new to the library. The books will be rotated on a
monthly basis and may be circulated while on display.

The following books have been received from Honingklip
Nurseries, Capetown, South Africa:

Rycroft, H.B. What Protea Is That? 1970.

Judd, Eric, What Aloe Is That? 1967.

Rousseau, Frank, The Proteaceae of South Africa. 1970.

Rawe, Rolf, Succulents In the Veld. 1968.

Rice, Elsie Garrett, Wild Flowers of the Cape of Good
Hope. 1950.

Rourke, J. P., Taxonomic Studies on Leucospernum, R.
Br. 1972.

Williams, J. M., A Revision of the Genus Leucadendron
(Proteaceae). 1972.

Harrison, Richmond E. Handbook of Trees and Shrubs.
1974.

Batten, Auriol, Wild Flowers of the Eastern Cape
Province. 1966.

van der Spuy, Una, Wild Flowers of South Africa for the
Garden. 1971.

van der Spuy, Una, South African Shrubs and Trees for
the Garden. 1971.

Eliovson, Sima, The Complete Gardening Book. 1974.

Reynolds, G. W. The Aloes of Tropical Africa and
Madagascar. 1966.

Plant Organizations

Are you planning any special events that are open to the
public? If so, please remember we are glad to help publicize
such events in the Newsletter. Our deadline is the tenth of
the month prior to the event.

Green Thumb Newsletter is published monthly by Denver Botanic Gardens,
Inc., 909 York Street, Denver, Colorado 80206. The Newsletter is included as a
benefit of membership in the Denver Botanic Gardens, regular membership dues
being $10.00 a year. Items for publication are welcome. The deadline for copy
to the editor is 2:00 p.m. on the 10th of each month preceding publication.
Editor - Margaret Sikes, 297-2547, Ext. 23.

GreellThUinb Newsletter DENVER botanic gardens, inc.

_ _ Copyright 1975

NUMBER 75-11 NOVEMBER 1975 TELEPHONE 297-2547

GARDENING TIPS FOR NOVEMBER

Except for a few more turns of the compost and some
minor pruning here and there, outdoor gardening has come
to a close and attention can be turned to some challenges in
indoor gardening.

FORCING BULBS

One of the most fun and rewarding indoor garden
occupations is forcing bulbs into bloom for winter-time
enjoyment. You need not be an expert to do it but a few
steps should be followed to ensure success.

Before going into the forcing procedure, let’s first
examine the life cycle of a bulb to better understand how
bulbs can be forced. First of all, a bulb is really a bud on a
very short stem with special food-storing capabilities. Under
proper conditions the “bud” forms roots shortly after plant¬
ing enabling the bud, which already contains the flowers and
leaves in miniature form, to elongate into a full-fledged
plant.

Some bulbs, like the paper white narcissus, are ready to
grow without any special treatment. Simply place them in
moist sand, gravel or soil and watch them develop into a
flowering plant in as little as six weeks. Other bulbs, such as
most tulips, hyacinths and daffodils will require a cold
treatment in order to break a natural dormancy just as the
buds on outdoor woody plants require. To force the bulbs,
they should be planted in pots containing moist, well-drained
soil and kept in a cool area (40°F best) for several weeks.
Most tulips should be given 13-15 weeks of cold treatment;
hyacinths and most daffodils need only 6-8 weeks. Most
important is keeping the soil moist, but not overly wet,
during the cold period.

After the cold period, the pots should be moved to a
place where room temperature is about 60° - 65 °F (such as
a basement) until the top growth is about 3 or 4 inches tall.
They then can be moved to a brighter and warmer room for
forcing into bloom.

It is also possible to buy bulbs already pre-treated for
forcing. Such bulbs should be checked carefully, however,
before purchase. Avoid bulbs that have already put out top
growth and those that are bruised or showing fungus growth
on the surface.

WINTER WATERING

This fall has been very dry and it is not possible to
predict the kind of winter we will have. If dry conditions
continue, deep watering of all your trees and shrubs is in
order. Special attending needs to be given to the shallow-
rooted trees such as birch, maple and linden (basswood);
shrubs such as lilac, Amur maple, euonymus and viburnum
and all evergreen types. I prefer to water using a hose-
attached soil needle like the Ross Root Feeder. This device
puts the water where the roots are, thus not only conserving
on water but also aerating the root zone at the same time.
Caution: Do not attempt to water during subfreezing
temperatures.

DELAY EARLIEST BLOOMERS WITH MULCHES

Plants that tend to bloom too early in spring can be
delayed as much as two weeks by applying a mulch to the
soil surface as soon as the ground is thoroughly frozen. For
best results, use a mulch material that is coarse and does not
tend to cake or compact. One of the best is wood or bark
chips. These can be applied to a depth of 4 or 5 inches over
the root zone of the plants or, in the case of early bulbs,
over the entire flower bed. The mulch acts as an insulation
to prevent an early thaw of the soil. The mulch will also
reduce water loss from the soil and thus reduce the need for
supplemental watering during “open”, dry periods in
February and March.

HOUSE PLANTS

Now that cold weather is here and our home furnaces
are fired up, it is a good idea to watch your house plants
carefully. Usually, the humidity in the home drops
drastically when the furnace comes on, particularly if you
have forced-air heat. At this time of year, sunlight is of
shorter duration although it can be just as intense in early
morning and late afternoon. The reduced light tends to
reduce the demands of a plant for water, the reduced
humidity will increase water demands. In a sense, house
plants become “confused” and begin to develop problems
such as leaf drop and browning of the leaf margins. To avoid
this, try gradually reducing the frequency of watering to
help “harden” the plants. When you do water, however,
apply water liberally so that a quantity will flow out of the
drainage holes in the bottom of the pot. This surplus water
should be discarded to avoid it being drawn back into the
pot and thus reduce chances of soluble salt accumulation.
(The white crust seen on the soil top and along the pot rim.)
Most important is to avoid overwatering (too frequent) and
keep house plants away from heaters and cold drafts.

Reminder: Now is a good time to clean up elmwood
debris. All elm wood having bark attached should be
destroyed before spring to avoid emergency of the elm bark
beetle, carrier of Dutch elm disease.

Dr. James Feucht

Dr. Miriam Denham will be offering an Intensive Course
in Botany in winter. This Denver Public School course, to be
taught at the Denver Botanic Gardens, is specifically
designed to help in the training of non-botanist teachers. The
classes will start on Monday, January 12, from 4 to 6:30
p.m., Classroom B.

Some topics to be covered in the 10-week session
include: Use of the microscope, preparation of fresh plant
materials, and the use of prepared slides to examine plant
cell types and tissues; flowering plant organs; vegetative and
reproductive structures; brief survey of the plant kingdom;
basis life processes: effects of light and nutrients needed for
growth: propagation with examples of easily grown plants
for demonstration of principles.

A total of two hours graduate credit will be given. For
further information, call Dr. John Brennan, 266-2255, Ext.
488.

Christmas Sale
November 21-22

It’s the twelfth year of Christmas for Botanic Gardens
Gift Shop as volunteers prepare for their annual pre-
Christmas sale Nov. 21 and 22 in Boettcher Memorial
Center, 1005 York Street. Sponsored by Associates of
Denver Botanic Gardens the sale will be held from 10 a.m.
to 4:30 p.m. each day.

Bedecked with festive handcrafted treasurers, yuletide
gifts, zesty gourmet treats and botanical harvests Horti¬
culture Hall, the Gift Shop near the Conservatory and the
Lobby Court emerge as Holiday Mall for discriminating
shoppers, happy that a gift from the Gardens is a gift to the
Gardens.

Ornamentally, pine-scented angels, wreaths and
Christmas trees have been fashioned of cheery calico by
members of the potpourri workshop while miniature bird
feeders are the creation of arts and crafts workshop
volunteers. The exotic jewel-studded stars-over-Persia that
adorned last year’s holiday decor will be offered — it’s
traditional and they’re sensational! Birds or ponies in merry
felts, handpainted angels in soft pastel, tiny cornhusk
figurines and wooden drummer boys will be among the
variety of trim-the-tree items.

Holiday Treasures include one-of-a-kind heritage wreaths,
table pieces, dainty wreaths of seeds and cones for candle
rings or wall hangings, framed miniature floral arrangements
for desk or dresser.

Fragrance Gifts. Gardenia, a new fragrance, will be
introduced to the Shop’s repertory of potpourri in domed
glass or brass and glass containers, sachets and tranquility
pillows. Bulk potpourri will be available only in rose
fragrance. Here, too, will be found pomander kits, fruit or
floral scented glycerine soap as well as traditional frank¬
incense and myrrh.

Gift That Grows. Pots of Cymbidium orchids to start an
orchid fancier on his way or to enhance a modest Wardian
case, will be for sale.

Herb Vinegar and tarragon vinegar are cherished gifts for
culinary enthusiasts. Brewed from a generations-old recipe by
members of Botanic Gardens Guild, tasty vinegars have
earned the funds to plan, plant, develop and expand the
Guild’s nation ally -known herb garden, an integral segment of
our Gardens’ landscape plan.

Other Gourmet Gifts include herb salt, vanilla beans,
cinnamon sticks in addition to mugs, pitchers, teapots,
casseroles and bowls with herb or floral design, decorative
linen towels and hot pot holders, placemats, tiles and
fun-and-fancy serving dishes — ceramic celery, carrots,
asparagus or peas.

Children’s Gifts. Suggested are calico-critter jump ropes,
a hardwood doll that swims and an acrobatic bear, friction
toys and Aunt Pettitoes, the newest addition to a complete
Beatrix Potter collection. Potter books are now available in
paperback as well as hardcover editions. A series of German
fairytale figures will be found in natural wood finish.
Whimsical turtles and planters resembling caterpillars, snails
and kittens would cheer an adult or youngster.

Jewelry. Unusual seeds, beads and clay medallions with
nature patterns have been fashioned into neckpieces, brace¬
lets and earrings. Ghost beads of juniper berries are made by
Navajos living near Bluff, Utah. Other items have been
chosen in petit point — rings, manicure and sewing sets.
Picture frames, pill boxes, pendants and brooches will be
available in mosaic. A centennial aspen pendant in gold and
the traditional aspen pins, earrings and tie tacks in gold,
silver or lucite will be featured.

For Men or Office. Laser-engraved walnut desk
accessories such as pencil holders, business card dispensers
and paper weights; ceramic humidors, letter holders and
smoker sets with gamebird designs; stone boxes with inlaid
floral patterns; lucite paper weights incorporating natural
materials and exquisite Kashmir containers would be
appropriate.

Books. More than 400 titles suggest volumes for the
very young as A is for Annabelle and 1 is One byTashh
Tudor; The Life of Marshes, Fishes or other subjects in the
Natures Way series; Pesman’s Meet the Natives for amateur
wildflower botanists to Harrington’s Manual of Colorado
Plants for the serious scientist. Plans, Parks and People, a
history of Denver’s Parks and landscapes as told by S. R.
DeBoer as well as Vegetable Gardening for inflation-weary
families are both special issues of The Green Thumb and
excellent stocking stuffers. Books about ornamental plant
designs for needlepoint and books on dyeing with plants
would delight creative stitchers.

Stationery and Calendars. The Junior League’s calendar,
Colorado - Then and Now, historical sketches in sepia tones
and Colorado in Color, a centennial calendar, will be avail¬
able. Note papers with botanical themes, decorative seals of
wildflowers and others of birds are inexpensive items. A
flower card game as well as bridge and playing cards
featuring 54 identified birds will be offered at the sale.

Gifts for Garden or Lanai are copper fountains, con¬
temporary in design, for indoors or out; planters in ceramic
and pottery in matte finish or glossy sheen; wicker plant
stands; windchimes of brass, wood or lucite; ceramic friend¬
ship pots to brighten a window garden.

Classic Accessories, gifts for home, have been selected
from near and far: Peking glass trees, Simi stone figures from
Holland; Venetian glass; Limoge drawer pulls and switch-
plates; scenic cork carvings from India; quaint wall plaques
from St. Andrews Priory (biblical figures in muted tones);
cachepots, bowls and boxes in shell design; sliced minerals
with tiny 14 karat figures; St. Francis in many sizes and
finishes; birds, butterflies and animals in alabaster, bisque,
ceramic or wood; leaded European stained glass in one-of-a-
kind designs.

Do-It-Yourself Yuletide Gifts. Cones, pods and dried
natural materials have been assembled by members of
Around the Seasons Club for their annual project. Plumed
cockscomb, moneyplant, teasel, pampas grass are a few of
many offerings for flower arrangers; sweet gum balls, acorns
and chestnuts are sought-after supplies for craftsmen.

Again, a gift from the Gardens is a gift to the Gardens,
for all proceeds from this annual event benefit Denver
Botanic Gardens.

One more thing to remember is a membership in the
Gardens. The Gardens are open every day of the year
(except Christmas Day and New Year’s Day), and the hours
are listed below:

The Boettcher Memorial Conservatory: 9 a.m. to 5 p.m. daily
The Helen Fowler Library:

9 a.m. to 5 p.m. Monday through Saturday
1 p.m. to 5 p.m. Sunday
The Herbarium Display Area: 9 a.m. to 5 p.m. daily

The Herbarium: 9 a.m. to 3 p.m. on Tuesday,

or by appointment

The Gift Shop:

10 a.m. to 4 p.m. Monday through Saturday
11 a.m. to 4 p.m. Sunday

The Denver Botanic Gardens consists of three units: The
York Street Unit; the Montane Unit on Bear Creek, above
Evergreen; and the Alpine Unit on Mount Goliath. Each
offers, in season, a different display of plant materials.

The Helen Fowler Library offers many books on
botany, horticulture and related subjects, as well as period¬
icals. The needs of gardeners of every level have been
considered. Circulation is limited to members.

Members receive The Green Thumb quarterly magazine
and the monthly Green Thumb Newsletter carrying
announcements of varied and interesting activities. A
Schedule of Education Courses will be mailed to all
members, listing free classes and those in which members
may enroll at a discount.

Those of you who attended Miss Kasumi Teshigahara’s
Ikebana demonstration and workshop know what a treat it
was to watch a real artist at work. Visitors came from San
Francisco, Portland, Conroe and Dallas and of course from
many areas in Colorado to leam from her.

Students who wish to learn more about this oriental art
form, may be interested to know that several different
schools of Ikebana are taught in the Denver area. For further
information as to teachers and locations, please call Mrs.
Jean Blackledge, 756-7242.

“The Redwoods,” the beautiful and majestic giants of
the forests, will be featured on November 8 at 1:30 in
Classroom C. This twenty-minute color film made by the
Sierra Club has won International honors including the
Academy Award. Free.

November Classes

A slight change has become necessary in the class listing
for Mr. Hannigan, who was to teach the House Plant classes,
is out of town. Mr. Dave Lankhorst, who worked in the
Conservatory prior to his retirement, and Dr. Helen Zeiner,
Chairman of the Herbarium Committee, will replace him. Mr.
Lankhorst will teach the Monday class, November 3-24, 10
to noon and Dr. Zeiner, the Wednesday one, November 5-26,
also 10 to noon — Room A. The cost is $10.00 for members
and $15.00 for non -members. As of this writing each class
shows twelve enrolled so do not delay too long in signing
up. Limit 25 in each.

And a sneak preview of the Winter List of Classes shows
a Tour of the Applewood Seed Company in early December;
Botany for non-Majors in conjunction with Metropolitan
State College, starting on January 6, and two Hobby Green¬
house Management classes. Watch for these and much more
— coming soon.

The editor is extremely sorry that Mr. George Cranmer’s
name was misspelled in the Autumn issue of the Green
Thumb Magazine. Our deepest apologies.

ANIMAL EATERS CAGED AT THE GARDENS

Plants eat animals, you know. At least, some of them do.
And we have those kind of plants at Denver Botanic
Gardens. You can see these carnivorous plants, at any time,
in a large display case on the balcony above the entrance to
the Conservatory.

There are some twenty plants in the case, all strange,
unusual and fascinating. Perhaps the best known of the
animal eaters is the Venus Fly-trap, Dionaea muscipula, a
modified leaf which produces inviting nectar along its inner
surface. Insects which are lured into the trap, if large
enough, brush bristly trichomes which trigger the trap. On
closing the cilia which line the leaf edges intertwine like the
fingers of clasped hands, preventing the victim’s escape, but
allowing tiny bugs to wriggle free. The leaf gradually tightens
its hold and begins secreting digestive enzymes; the process
may take 8 or 10 days. Linnaeus called this plant miraculum
naturae.

Other captive carnivores in the case are the Sundews,
Drosera tracyi, D. filiformis and D. intermedia, from the gulf
and eastern coasts of the U.S.; the Cobra Lily, Darlingtonia
calif ornica, from the west coast; the Pitcher Plants,
Sarracenia minor the dwarf, S. alata — winged, S. rubra —
red, S. purpurea — purple, and S. psittacina — parrot-leaved,
all from the southern part of our east coast. Two foreigners
are included, a pitcher plant, Nepenthes x superba, from
Malasia, and the Common Bladderwort, Utricularia vulgaris,
from Eurasia.

All but one of the above are bulbs and must be kept in
cold storage during dormancy for two or three months each
year. The Botanic Gardens case is kept at room temperature;
in a greenhouse the plants should be grown at 60 degrees.
The soil mixture in the case is one-third acid peat moss,
one-third sphagnum moss, and one-third coarse sand.
Distilled water is used for moistening and the case holds the
moisture well. Light is furnished by three fluorescent lamps
which burn about 15 hours per day. It isn’t necessary to
furnish meat for the carnivores. No chemicals are ever used
on these plants, neither sprays or fertilizers. The green cover
around the plants is Selaginella, an interesting plant in its
own right.

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Thank you N.F.I.!

The Netherlands Flower Bulb Institute, Inc. has recently
written the Denver Botanic Gardens to say that they will be
shipping more of their fine quality bulbs for our spring
display. Besides fifty varieties of tulips and 3200 Narcissus
bulbs, 1200 Muscari are coming as are the following varieties
of hyacinths:

1200 Bismarck
400 Delft Blue
2000 Blue Jacket
1200 Carnegie
2000 L’lnnocence

400 Amsterdam
800 Jan Bos
800 Pink Pearl
400 Princess Margaret

Memorial gifts have been received in remembrance of:

Mr. Brown W. Cannon
Mrs. Mary Grant Coors

The Board of Trustees is pleased to announce the
election of the following new members:

Mr. Newell Grant

Mrs. Richard W. Hanselman

Mrs. Norman F. Patrick

You must see tire massed blooms in the Lobby Court
this month! Eight centuries ago in China, Fan Cheng-Ta
wrote:

And now the Day of Double Brightness comes,

With Autumn’s festal flowers, chrysanthemums

Night long endures the unexpected frost,

A sign that autumn nears her end at last:

The woods, where yesterday only greenness was,

Wear now a richly -embroidered silken dress.

Here in my orange-garden’s secret air,

Another transformation is astir:

Hidden among the leaves of emerald

Ten Thousand golden spheres are safe in fold.

To make this display, requires months of work. The
plants were ordered in winter, grown in tire greenhouses all
summer where they were heavily fertilized and pinched and
shaped repeatedly. Some were grown on frames and others
in hanging baskets or pots; some also underwent bonsai
training. The work continued into the fall when they were
carefully shaded, for chrysanthemums are a light sensitive
plant.

Look for the myriad varieties of color and shade as well
as such types of flower form as spider, spoon, exhibition
incurve, reflex, pom pom, and saga.

Come during the Christmas Sale, of course, but since we
usually have such large crowds then, it might be wise to
choose another more peaceful time to view the
chrysanthemums.

Green Thumb Newsletter is published monthly by Denver Botanic Gardens,
Inc., 909 York Street, Denver, Colorado 80206. The Newsletter is included as a
benefit of membership in the Denver Botanic Gardens, regular membership dues
being $10.00 a year. Items for publication are welcome. The deadline for copy
to the editor is 2:00 p.m. on the 10th of each month preceding publication.
Editor — Margaret Sikes, 297-2547, Ext. 23.

GreeJ) ihllUlh MMer DENVER botanic gardens, inc.

Copyright 1975

NUMBER 75-12 DECEMBER 1975 TELEPHONE 297-2547

GARDENING TIPS FOR DECEMBER

Selecting a Christmas tree is hardly considered gardening
but then if you plan to use a live tree, it would certainly
involve some gardening. In recent years there has been an
increase in interest in using live Christmas trees; that is,
spruce, pine and fir purchased in bushel baskets, then used
as Christmas trees to be later planted in the yard. This
practice has been promoted by some in the interest of
ecology but let’s take a look at how really ecological it is. In
the first place, the cut trees that you buy should not be
considered a waste of natural resources. Many are grown by
Christmas tree growers as their livelihood and used only for
that purpose. Others are cut as a thinning operation in our
natural forests. Thinning is a necessary practice in our forests
to promote healthier tree stands.

Using a live tree and planting it in your yard may sound
like a good idea but unfortunately, statistics have shown that
only a small portion of these trees survive after they have
been planted out in the yard. One of the difficulties is that
the tree is held in a warm location for a week or more and
this sometimes causes the plant to come out of its natural
dormancy, making it vulnerable to cold temperatures when
placed out of doors. Another problem is that the trees are
often allowed to become too dry and the root system is
frequently disturbed more than usual because of the extra
handling in moving it indoors and out.

If you are planning to buy a live tree this year, you
should prepare the planting site now before the garden
freezes and save the backfill soil in a location where it will
not freeze. The hole should be dug and covered with boards
to keep someone from falling into it until the tree is planted
out.

Most of the trees purchased will be in bushel baskets.
They should be kept moist and in a cool location such as a
garage, until shortly before Christmas time. It is best to keep
the tree indoors for not more than 3 days. That is, the day
before, the day of, and the day after Christmas. After that
time, take the tree to a shaded outdoor location or plant it
directly in the planting site if the weather permits. Avoid
planting the tree out during subzero weather. After placing
the tree in the hole, break the rims of the basket and
remove all but the bottom. After planting the tree, it should
be watered in and a mulching material such as woodchips
should be applied to a depth of 6 inches.

If you are planning to use a cut tree, try to find the
freshest tree available in order to reduce fire hazards.
Douglas fir, true firs such as Concolor, will hold their
needles very well but it’s best to avoid spruce because they
are prone to early needle-drop, they create a fire hazard and
they make a mess that is difficult to cle^n up in the house.

When selecting your tree, one way to tell its freshness is
to thump the tree on the ground several times and watch for
needles to drop. If only a few drop off, it is probably a
pretty fresh tree. If you purchase your tree several days
before you plan to take it indoors, submerge the base in a
bucket of water, after first making a fresh cut several inches
back from the old stub. Keep the tree in a shaded area.

Caring for your Poinsettia

The poinsettia is a popular plant this time of year
because it is a traditional flower for the Christmas season.
Actually, the use of poinsettias for the Christmas celebration
is not a recent custom because it dates back as far as the
17th Century. The Franciscan priests are considered the first
to use them for the Christmas celebration in the nativity
procession, Fiesta of Pesebre.

The poinsettia is native to Mexico, first cultivated by
the Aztecs. It was introduced into the U.S. by our first
ambassador to Mexico, Joel Roberts Poinsett. Thus the name
was given to this plant in this country. The Aztecs gave it a
much more complicated name: Cuetlaxochitl.

Poinsett sent some of the plants to his home in
Greenville, S.C. in 1825. Its popularity gained ever since,
particularly with the development of improved varieties,
largely the responsibility of Robert Ecke, a family of
poinsettia growers and hybridizers who are still the major
producers in the U.S. today.

The Ecke family, over the years, has developed
poinsettias other than the traditional red. It is now possible
to purchase white, pink and one close to chartreuse.

Actually, the colors of poinsettias are not the result of
the flowers themselves. The colorful portions, which may be
confused as petals, are actually modified leaves called bracts.
The real flowers are rather inconspicuous yellow-green
buttons in the center of the bracts.

Being a member of the spurge family, a group which
characteristically produces a white, latex-like juice, the
poinsettia has gained a reputation for being poisonous.
Apparently, some of the original varieties were, but recent
research has shown that the toxin present in poinsettias, if at
all, are no cause for worry as a house plant.

If properly cared for, poinsettias will last well through
the Christmas season and can even be sustained long enough
to plant in the yard in the spring. In the home they should
be kept in a bright spot but not in direct sunlight. Avoid
drafty areas such as doorways but keep them away from
heaters and other sources of heat including the top of a TV
set. Poinsettias will perform best if kept on the dry side. Let
them go to the point where the soil feels dry to a depth of
one-half inch.

Water enough so that the water runs out of the drainage
hole at the bottom of the pot. Any water that collects in
the basin beneath the drainage hole should be discarded.
This will prevent the surplus water, which usually contains
dissolved salts, from being drawn back into the pot. The
dissolved salts will injure poinsettias. Ideal temperatures for
poinsettias are 68 degrees F. to 62 degrees F. at night.

Merry Christmas and A Happy New Year!

Dr. J. R. Feucht

A 30-Minute color film produced by the Colonial
Williamsburg Foundation on the Flower Arrangements of
Williamsburg will be shown on December 13 at 1:30 p.m.
in Classroom C.

o Merry" Christmas and Hfappy”
Wen/' ‘Year to all from tlie staff
of ttie cj Denver ^Botanic Qardens.

First Announcement

The Denver Botanic Gardens is pleased to announce a
three week trip to Great Britain in 1976. Plans are now
underway to depart on May 23rd and to spend 22 days
touring England and Scotland.

The famous gardens of Kew, Wisley and the Royal
Botanic Garden in Edinburgh are on the list and of course
the group will also attend the Chelsea Flower Show.

A mailing will be sent to all the membership with more
information in the very near future.

THANKS AGAIN.

A grand time was had by all at The Associates Annual
Meeting. The volunteers who attended heard interesting
reports, ate good food and enjoyed a fascinating program.
(By tire way, Charles Marden Fitch’s newest book, The Com¬
plete Book of Houseplants Under Lights, is now available in
the Gift Shop.)

Recognition was given to the many volunteers who have
donated hours of their time to the Denver Botanic Gardens.

500 HOUR PINS

Frances Carswell

Gift Shop

511

Laura Dawson

Gift Shop

508

Madeleine Gately

Library

617

Betty Gilliom

Gift Shop

785

Bernice Jacobs

Gift Shop

502

Jean Kellogg

Gift Shop

595%

Peg Milroy

Library

619

Margaret Polak

Library

557

Lucille Pollard

Library

522

Mary Taylor

Library

524

Frances Warden

Library

580

Charlotte Wendell

Guide &

Hostess Desk

636

1,000 HOUR PINS

Geneva Eldridge

Library

1,075

Gloria Falkenberg

Gift Shop

1,016

Marie Hyland

Gift Shop

1,053

Bernice Millard

Library

1,210

Thanks again, and thanks, too, to all who worked so hard to
make the Christmas Sale the success it was.

DECEMBER CLASSES

Thinking about enrolling in the Guides Class in January
but wondering how the tours are handled? Join one and see.
Some scheduled groups are on December 1 and 3 at 10:30
a.m., both for 5th Graders and on December 8 at 10:30 a.m.
for 4th Grade. Meet the group in the lobby of the
Conservatory.

Remember the Tour to Applewood Seed Company on
December 2. Those who wish may meet at 9 a.m. at 909
York Street, or if you live on the west side, you may prefer
to go directly to 833 Parfet. Turn north off 6th Ave. at
Simms, go one block to 8th and turn east to Parfet Street.
There is a large complex on the northwest corner — follow
the Applewood sign to the west side of that building. Free,
but limited to the first twenty people who call in.

Children who enroll in the Christmas Swags class will be
able to contribute something made by themselves to their
own family. We need the registrations early so that we may
provide the correct amount of greens, ribbons and other
trimmings so don’t delay. The class will be held on December
6 at 9 a.m. in Classroom B. Cost $2.50. Limit 17. Ages 12
through 16, please.

Another free class, Traditions of Plants of the Holiday
Season will help get us all in the mood. Holly, the chief
plant emblem of Christmas, has been mentioned in many
superstitions since the time of Saturnalia. Poinsettia and
mistletoe are also prominent plants used at this season. All
welcome at 10 a.m., December 9, Classroom A.

In the Natural History of Selborne you will find:

“The standing objection to botany has always been that
it is a pursuit that amuses the fancy and exercises the
memory, without improving the mind or advancing any
real knowledge; and where the science is carried no
farther than the mere systematic classification, the
charge is but too true. But the botanist that is desirous
of wiping off this aspersion should be by no means
content with a list of names; he should study plants
philosophically, should investigate the laws of vegeta¬
tion, should examine the powers and virtues of
efficacious herbs, should promote their cultivation; and
graft the gardener, the planter, and the husbandman, on
the phytologist. Not that system is by any means to be
thrown aside; without system the field of nature would
be a pathless wildnerness; the system should be sub¬
servient to, not the main object of, pursuit.”

Enroll in Carol Steele’s class, General Botany for non-
Majors and see how well she follows White’s admonition.
The class will be from January 6 to March 11 from 1:20 -
2:50 p.m., Tuesdays and 1:20 - 5:10 p.m. Thursdays. For
college credit, call 292-5190, Ext. 246, or for no credit and
information on cost, call 297-2547. Limit 15 students.

DENVER BOTANIC GARDENS
CALENDAR OF EVENTS
DECEMBER, 1975

DECEMBER

2)*

10:00 a.m.

Education Building — Herbarium

Herbarium Committee Meeting

2)*

1:00 p.m.

Botanic Gardens House — Dining Room

Editorial Committee Meeting

2)

7:30 p.m.

Education Building — Lecture Room “C”

Denver Audubon Society

2)

7:30 p.m.

Education Building — Horticulture Hall

Rooms “A” & “B”

Neighborhood Crime Prevention Day

3)*

9:30 a.m.

Education Building — Lecture Room “C”

Gardener Training Program

“Flower Beds” — Mr. Ron McKenzie

4)

7:30 p.m.

Education Building - Lecture Room “C”

Colorado Open Space Council (Board Meeting)

4)*

7:45 p.m.

Education Building — Horticulture Hall

Denver Orchid Society

5)

1 1 :00 a.m.

Botanic Gardens House — Main -
Dining & Kitchen

Civic Garden Club

6)*

9:00 a.m.

Education Building — Lecture Room “B”

Christmas Swags — Mrs. Audrey Stites

(Students age 12 thru 16 - Limit 17)

6)

9:30 a.m.

Education Building - Lecture Room “A”

Nature Conservancy

★ ★★★★★★ik-

★ ★

8)

7:30 p.m.

Botanic Gardens House — Main Room

Sierra Club (Wildlife Workshop)

9)*

9:30 a.m.

Education Building — Lecture Room “B”

Civic Garden Club — Division “C”

9)

10:00 a.m.

Education Building — Lecture Room “A”

Traditions of Plants of the Holiday Season

Dr. James Jackson

9)*

4:00 p.m.

0

Botanic Gardens House — Dining Room

Executive Committee Meeting

9)

7:00 p.m.

Education Building — Lecture Room “B”

House Plant Class — Dave Woodward
(For information call Denver Free
University — 832-6688)

9)*

7:30 p.m.

Education Building — Lecture Room “A”

Swingle Study Group

10)

8:30 a.m.

Education Building — Horticulture Hall

Landscape Management Workshop

10)*

9:30 a.m.

Education Building — Lecture Room “C”

Gardener Training — Refresher Course

10)

7:30 p.m.

Education Building — Lecture Room “C”

Colorado Open Space Council

Wilderness Workshop

10)*

7:30 p.m.

Botanic Gardens House - Dining Room

Landscape Industry Council

11)*

3:30 p.m.

Botanic Gardens House — Dining Room

Development & Public Relations Meeting

12)*

6:30 p.m.

Education Building — Horticulture Hall

Parks & Recreation Christmas Party

12)

7:30 p.m.

Botanic Gardens House — Main -
Dining & Kitchen

Denver Dahlia Society

13)

10:00 a.m.

Education Building — Lecture Room “B”

Colorado Organic Grower’s & Marketer’s
Association

13)

1 :30 p.m.

Education Building — Lecture Room “C”

Film: “Flower Arrangements of Williamsburg”

13)*

6:00 p.m.

Botanic Gardens House — Main -
Dining & Kitchen

Colorado Bonsai Club

★ ★★★★★★★

★ ★

16)

7:00 p.m.

Education Building — Lecture Room “B”

House Plant Class — Dave Woodward

(For information call Denver Free
University — 832-6688

CALENDAR OF EVENTS FOR DECEMBER (Continued)

DECEMBER

17)*

9:30 a.m.

Education Building — Lecture Room “C”

Gardener Florists Refresher Course
“Watering”

17)

7:30 p.m.

Education Building — Lecture Room “B”

Colorado Open Space Council
(Air Quality Workshop)

17)*

7:30 p.m.

Botanic Gardens House — Main -
Dining & Kitchen

Men’s Garden Club

18)*

10:00 a.m.

Botanic Gardens House — Main -
Dining & Kitchen

Around the Seasons Christmas Party

18)*

6:30 p.m.

Botanic Gardens House — Main Room

Colorado Chapter of American Society
of Landscape Architects

18)

7:30 p.m.

Education Building — Lecture Room “C”

Organic Gardening Club of Denver

★ ★

23)

7:00 p.m.

Education Building — Lecture Room “B”

House Plant Class — Dave Woodward
(For information call Denver Free
University — 832-6688

MERRY CHRISTMAS!

&

HAPPY NEW YEAR!

1976

JANUARY

3) 9:30 a.m. Botanic Gardens House — Main Room Gloxinia Gesneriad Growers

*Members or enrollees only.

Finished with your Christmas shopping — taken care of
everyone on your list? What about a present to the Denver
Botanic Gardens? If you participate in Midland Federal
Savings Save and Share Program that is what you may do.
When you open a savings account at Midland, or when you
add to an existing account, they will send a check to the
charity of your choice. Regulations permit Midland Federal
Savings to send donations in amounts shown below to any
charity recognized by the Internal Revenue Service. Payment
is made by check with your name' as donor.

Amount of Deposit Amount of Gift to Charity
$ 250.00 $ 2.50

1,000.00 5.00

5,000.00 10.00

Midland will also make a donation of its own to the same
charity.

LONGWOOD GARDENS
PLANT MATERIALS SUMMER LABORATORY

College students throughout America, majoring in the
Plant Sciences and particularly in horticulture, have an
unusual opportunity to gain practical work experience in the
field of ornamental horticulture in a special summer program
conducted each year at Longwood Gardens, Kennett Square,
Chester County, Pennsylvania. This program is sponsored
jointly by Longwood Gardens and the University of Dela¬
ware at Newark, Delaware.

Longwood Gardens, operated by the non-profit, philan¬
thropic Longwood Foundation, Inc., is one of the out¬
standing gardens of America. With extensive greenhouse
facilities, as well as outdoor plantings, it features year round
displays of superbly grown horticultural materials.

Students participating in the 10-week program are
employed for the summer by Longwood Gardens, but are
enrolled for purposes of obtaining college credit through the
Department of Plant Science of the University of Delaware.
During the course of the summer, students are assigned work
for periods of a week or two in each principal horticultural
location at Longwood Gardens, including the displays in the
main greenhouses and experimental greenhouses, the nursery
and the perennial, annual and vegetable gardens. In addition,
students are required to attend a series of lectures on
practical horticultural subjects by members of the staffs of
Longwood Gardens and the University of Delaware. They
also participate in a weekly session on identification of more
unusual plant materials grown at the Gardens. A final
written report is required of each participant at the end of
the summer. This course carries three college credits from
the University of Delaware.

Students accepted and enrolled in the Longwood
Gardens Summer Program work a 35-hour week for which
they receive an hourly wage of $2.00. Rooms are available at
the Gardens for male and female students at $35.00 per
month. No meals are served at the Gardens, but are available
close by.

Because of limited enrollment, only outstanding students
will be selected for this program. Selection of candidates will
be on the basis of recommendations of advisors, stated
objectives in the field of horticulture and class (seniors and
juniors being given preference over lower classmen). Formal
applications in writing, accompanied by a copy of their
college transcript must be received by February 1 of any
year, at the Department of Plant Science, University of
Delaware, Newark, Delaware, 19711.

SILVER AWARD RECEIVED
AT THE ORCHID SHOW

The Denver Botanic Gardens was awarded a silver tray
and goblets set for the best Educational Exhibit in the
Southwest Regional Orchid Growers Association show held
in Denver October 8-11. Orchid species were used from the
collection which has been gathered over a number of years
and included many varieties which had been collected by Mr.
and Mrs. William Thurston on trips to Mexico and donated
to the Gardens.

D.E.D. UPDATE

The Colorado State Forest Service has again conducted a
survey of infected trees in the Denver area. Dutch elm
disease is on the decline this year when compared to last
year’s figures.

Total diseased or dead trees in Denver for 1975 is two
thousand as compared to six thousand in 1974. The survey
showed that in Adams and Arapahoe Counties 579 diseased
trees were located, resulting in a total of 2,579 diseased
trees.

Several factors account for the decline. Homeowner
desire to remove diseased trees promptly is the main factor.
The dry winter, unusual spring and summer weather condi¬
tions are also contributing factors.

Now is the time to remove those dead and diseased
trees. If all dead and diseased trees are removed by next
spring, Denver area residents can expect a further decline in
the disease in 1976.

And, according to The Avant Gardener of March 1975,
a promising new hybrid elm which is resistant to D.E.D. is
being developed. This cross of Ulmus hollandica var. vegeta
and U. carpinifolia grows rapidly in a wide range of soils,
tolerates drought, pollution, soil compaction and restricted
roots. It has dark green foliage, grows 60 to 80 feet and has
an upright branching form with a dense compact crown.

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NEW GARDEN FOR THE CENTENNIAL YEAR

The Denver Botanic Gardens are proud to announce a
new addition to their old and treasured herb garden. The
beautifully designed new garden contains a memorial sundial
dedicated to Persis M. Owen, who designed the original herb
garden in 1964. The Gardens are pleased to give such recog¬
nition to a person of her abilities and skills.

The herb garden is a self -sustained unit of the Gardens,
created and financed by Denver Botanic Gardens Guild, by
their work in the garden and by revenue-raising garden tours
in July and the sale of enormous amounts of herb vinegar at
the Christmas Sale on November 21 and 22.

The new addition was begun in 1972 with Jane Silver-
stein Reis heading the planning and development work at the
garden. A drinking fountain and. brick walkways have been
installed and a large arbor and benches are to be installed as
the third phase of the addition.

Development of the new garden is to provide more
room for those herbs, found throughout the entire world,
which have specific uses for culinary or medicinal purposes.
Some of the varieties are: The beautifully scented geraniums
with the sweetest of fragrances; three varieties of Basil and
even more than that of Thyme; the exciting scent of pine¬
apple mint with its overlay of pineapple on a background of
mint.

Among medicinal herbs is feverfew, usually a difficult
plant to track down. It’s growing in our garden. Feverfew,
Chrysanthemum parthenium, has uses as a warm infusion for
indigestion, colds, and even alcoholic d.t.’s. As a cold
extract, it may be used as a form of tonic. Another one,
Blood Root, Sanguinaria canadensis, is a small perennial herb
about six inches in height found in damp, rich soils. This
herb has uses as a sedative, stimulant and tonic. It also may
be used externally on sores and other skin problems. The
wrong dosage may be fatal.

Remember to say it “erb”, not “herb”.

Dan Brownson

HIGH SCHOOL INTERN AT THE GARDENS

There is a new face among the crowd here at the
Gardens. It belongs to Daniel Brownson, who is here because
of the Denver Public School Executive Internship Program.
This program is geared toward students working in the com¬
munity and allows them to test their interests and
participate in a full working day, four days a week. Then on
Fridays, Dan either has seminars with the other interns or
attends meetings at his own home school, East High. This
program is most beneficial for students and gives them a
head start in the occupation of their choice. Dan reports he
has both enjoyed and learned a great deal with the help of
the entire crew at the Gardens and he is looking forward to
the months to come.

Green Thumb Newsletter is published monthly by Denver Botanic Gardens,
Inc., 909 York Street, Denver, Colorado 80206. The Newsletter is included as a
benefit of membership in the Denver Botanic Gardens, regular membership dues
being $10.00/ a year. Items for publication are welcome. The deadline for copy
to the editor is 2:00 p.m. on the 10th of each month preceding publication.
Editor — Margaret Sikes, 297-2547, Ext. 23.

Green ihvmb Newsletter DENVER botanic gardens, inc.

Copyright 1976

NUMBER 76-1 JANUARY 1976 TELEPHONE 297-2547

GARDENING TIPS FOR JANUARY, 1976!

In this Centennial year, we will see many special efforts
by city park departments, institutions and private organi¬
zations to construct “Centennial Gardens”. Already under¬
way are plans for red, white and blue flag gardens and
similar patriotic designs for public display. There is no
reason why the home gardener cannot have a centennial
display to enjoy in the home grounds as well. With a little
planning and some careful selection of varieties of annuals,
the red, white and blue combination can be realized in a
showy flower border.

One of the tricks is to select annuals that will start
blooming at the same time and continue to have a steady
bloom all season. Petunias come to mind but there still isn’t
a really blue petunia on the market — tho ‘Blue Skies’ and
‘Sky Magic’ come close enough unless you are trying to be a
perfectionist. The tried and true variety ‘El Toro’ and ‘Red
Cascade’, as well as ‘White Cascade’ and ‘Snow Cloud’
provide the other two colors.

There’s no need to make a complicated design like the
American flag but it usually is a good idea to put your own
design on paper first. Use graph paper so that you can more
readily do it to scale and this will also make it easier to
determine the number of each type you will need.

Some other ideas for the patriotic display include the
‘Blue Mink’ variety of ageratum and its white companion
‘Summer Snow’ or the blue (nearly so) and white varieties of
alyssum ( Lobularia ). These low, edging plants can be nicely
used in combination with taller, red petunias, the brilliant,
red dwarf forms of cockscomb such as Celosia ‘Fire Glow’ or
the ‘Blaze’ variety of Verbena venosa.

It is often difficult to find just the exact colors and
varieties of annuals at any one garden center so why not try
growing your own? Now is a good time to thumb through
the seed catalogues and select the varieties you need and to
prepare for growing them indoors for an early start.

One of the biggest difficulties in growing annuals
indoors is securing adequate light. With insufficient light the
seedlings become thin and “leggy”, resulting in weak plants
which will rarely stand transplanting well. One solution is to
use artificial lights.

There are several commercial types of indoor lighting
shelves or trays available, but if you are planning to grow
annual bedding plants, avoid those with lights that cannot be
adjusted for height above the plants. Many commercial types
are designed for African violets with fixed lighting
assemblies. African violets need only 300-600 foot candles to
flourish, thus the distance of the lights to the plants is not
usually as critical as in annuals which require 1000 foot
candles or more.

The most versatile lighting arrangement has fluorescent
tubes suspended by chains that will allow adjustment of the
space between plants and light source as the plants grow.
With annuals, the lights will need to be as close as four
inches from the seedlings. (A pair of 40-watt fluorescent
tubes will yield 600-1000 foot candles at 4 inches when
tubes are new.)

While incandescent bulbs give off more light from the
same wattage as fluorescent, they create too much heat to
be placed close to the plants. Despite some claims, it is also

best to use “cool white” fluorescent rather than the pink
“Gro-lux” type. Research has shown that while the pink
tubes yield the proper light quality (in the red part of the
spectrum) it is at the expense of the light intensity.

Don’t be in a rush to start your annual bedding plants,
however. Set up the lights now and be content with indoor
foliage plants. Wait for starting annuals until March, at the
earliest. Otherwise, they will literally “grow you out of
house and home”!

After Christmas Care of Poinsettias.

Each year I receive numerous calls shortly after
Christmas to advise on the care of a poinsettia in the home.
Sometimes the caller is concerned because the plant is
already dropping its leaves. Until a relatively few years ago,
the advice would go something like this . . . “Keep the plant
on the dry side, watering only when the soil is quite dry to
touch, even 2 - 3 inches into the soil surface. Keep in cool
spot. Enjoy colorful bracts even without foliage and when
these fade — toss it out. You can try to start it over again
but the results rarely produce a spectacular show the second
time.” Now, with the new varieties on the market, this
advice is out-moded.

Perhaps you’ve noticed in the past few years that your
poinsettias seemed to last on even into early spring. This is
no accident or a case of rare individual plants here or there
having exceptional qualities, but rather the result of intensive
selection and breeding done principally by Dr. Robert N.
Stewart, USDA Research Horticulturist, Beltsville, Maryland,
and Mr. Paul Ecke, poinsettia grower in California. Actually,
much of the “breeding” has been selection and vegetative
propagation (rooting cuttings) of mutations. As a result you
can obtain shades of pink, white, and even speckled types.

More important has been the development of plants
with short, stout stems, large bracts (the actual showy part
which are modified leaves containing pigments called antho-
cyamin) and a remarkable lasting quality.

The new advice on poinsettia care now goes something

like this . “Water plants about every 4 days. Soon, new

side shoots will appear. Repot to a larger container in March
or April. Continue to water, adding houseplant fertilizer such
as fish emulsion about every other week. Move plant to a
semi-shaded location out-of-doors for the summer. (After
June 1.) To make it easier to handle, simply plunge pot into
garden soil. Before frost in fall, lift plant and pot and bring
indoors. (By now it is more a bush than a small pot plant.)
Keep plant in total darkness 14 hours each day and in
coolest part of the house (65 degrees F. is best. Try the
basement or crawl space.). When the bracts begin to show
color, bring them to the room you wish for display. You
should have a colorful array of bracts before and during
Christmas. You can continue this process each year on the
same plant until it outgrows your living room!”

As the plant gets larger, some pruning may be necessary.
Keep the prunings and root them for new plants. An easy
way is to take 6-8 inch stem pieces. Remove foliage on the
lower 2-3 inches. Place clean, moist sand in the bottom half
of large plastic bags (quart size or larger). Plunge base of

(Continued on back page )

Greetings From the Director

This message brings greetings and sincerest New Year
wishes for 1976 to all of you in the constantly growing
circle of friends and acquaintances of the Denver Botanic
Gardens. Included in this impressive throng are Mayor
McNichols, a staunch friend of the Gardens, the City Council
and other City officials, Manager Joe Ciancio of the Depart¬
ment of Parks and Recreation and his staff, the Board of
Trustees, the Staff of the Gardens, the nearly 3,000 mem¬
bers and hundreds of volunteers and friends. I wish to
express our deepest thanks to all of you, because it was a
result of your dedication and hard work that we can say
that 1975 was in many ways the most noteworthy year in
the existence of the Gardens to this time.

A complete story of the year’s achievements is too long
to tell here, and I hope that you will read the Annual
Report for 1975 to gain a full understanding of the many
ways in which the Botanic Gardens forged ahead in that
year. This will be sent to every member in the early spring
of 1976.

At this time, I would like to single out for special
commendation all of the members of the Staff of the
Botanic Gardens. They are the ones upon whom the great
responsibility rests to carry out the endless day-to-day tasks
which must be accomplished to keep a botanical garden
alive, growing and thriving. It is to them that I wish
particularly to extend at this time my personal thanks for
their loyalty, dedication and hard work. It is due, in the
final analysis to these people, that 1975 was a great year for
the Botanic Gardens.

Assistant Director Glenn Park has planned and overseen
the planting of many new trees and shrubs and thousands of
annuals. In the office we are all indebted to Ruth Hawkins,
Janet Wingate and Helen McCloskey; for our bookkeeping
and accounting we depend on Iris O’Connor. In the
Children’s Garden program, Beverly Nilsen was joined this
fall by our new Botanist-Horticulturist, Lee Schwade. In the
Maintenance section, Jerry Lehr has carried a great deal of
responsibility and has been capably assisted by Brian De
Haven. Carpenter Roy Nilsen has done much building and
cabinet work in the past year. Margaret Sikes has master-
-minded the Education Program. In the rapidly expanding
library, Librarian Solange Huggins has directed the opera¬
tions most efficiently. Grounds Foreman, Ken Okazaki, has
juggled his crew of Gardener-Florists and Utility Workers
among many different jobs during the year. His workmen
have included Bob Radosevic as maintenance mechanic and
equipment operator, and as gardeners Jim Carlson, Jerry
Cathey, Frank Chavarria, Richard Martinelli, Ken Price, and
A1 Rumpeltes. In the greenhouses, Richard Schimming has
served as plant propagator with the aid of Frank Garcia.
Larry Latta has directed the work in the greenhouses and
conservatory with the able help of Nancy Collins, Dave
Woodward, Gary Davis, and Frank Ragni. Dan Kruse and
Mark Nieto have done an outstanding job as custodians.
Andrew Pierce will be joining the staff as Superintendent of
the Conservatory and Greenhouses in January 1976.

All the persons mentioned above are permanent
employees of the Gardens. A number of temporary and/or
part-time employees have played essential roles this past year
in keeping the Botanic Gardens moving forward: John
Bermingham, Jr. and Cable Horan in the gardens; Carla
Mueller as a summer intern; Shirley Champman in the
Mycological Laboratory; Nancy Jackson in the Library; Jean
DeWoody aiding in record-keeping and making plant labels;
Kathleen Fletcher, secretarial; Dr. Patricia Smith, and Dr.

Hugh Wingate and Dr. Janet Wingate in editing The Green
Thumb ; Irene Vittetoe, the Children’s Garden, Dr. C. Eugene
Osborne and Wesley Woodward, the Gatehouse and the
Education Program; Rod Radosevic, custodial work and the
Gatehouse; Mrs. Georgia Hawkins, custodial work in the
Botanic Gardens House.

In addition to these persons, quite a number of
temporary, seasonal laborers did essential work in the out¬
door garden, tl]e greenhouses, or the conservatory.

It should be clearly understood that this list includes
none of the several hundred volunteers whose aid to the
gardens is indispensable, and who will be acknowledged
elsewhere.

In conclusion, let me say that all staff members are
frequently called upon to carry out many more duties than
just the ones they are credited with above, but space
prohibits mentioning them. We on the staff are looking
forward to another successful year together.

Dr. William G. Gambill, Jr.

The Christmas decorations were lovely, as always. Each
year Avalonne Kosanke, Fran Morrison and their committee
top the past years efforts. Thanks for all your help.

As is the custom, the Volunteers decorate the Lobby to
compliment the Lobby Court display itself. Remember how
beautiful the poinsettias were last year? Well, they are just as
spectacular now.

All year long the display features color and bloom. In
the dark days of winter, it is nice to think back. The year
started with the poinsettias followed by the vibrant reds of
Rieger begonias. In March, Easter lilies, cinerarias, and
cymbidium orchids were on display; next came spring bulbs
— tulips, hyacinths, and daffodils — interspersed with calceo¬
larias. At Plant Sale many ferns, bromeliads and others from
the Greenhouse collection were on display. Next came the
velvety blooms of gloxinias and again a begonia planting.
This time, however, besides Rieger, wax, tuberous and rex
were also shown. In August fuchsias and impatiens had pride
of place backed by podocarpus and other green foliage
plants, and finally the myriad of color and form of the
chrysanthemum led us into the Holiday Season and the two
poinsettia trees.

BOTANY CLUB - FRIDAY
January 16, 1976 - 7:30 P.M.

Classroom C

Slide Show — “Close-Ups in Nature"

Presented by Charles Major — Free and open to the public.

New Club

A membership meeting for the formation of a new
African Violet Club will be held at the house, 909 York, on
January 26 at 9:30 A.M. Anyone who is interested is
cordially invited to attend. For further information, please
call Emma Lahr, 771-5200.

DENVER BOTANIC GARDENS
CALENDAR OF EVENTS
JANUARY, 1976

JANUARY

3)

9:30 a.m.

Botanic Gardens House — Dining Room

Gloxinia Gesneriad Growers

6)*

9:30 a.m.

Education Building — Lecture Room “C”

Gardener Florists Refresher Course

Dr. Jackie Butler, C.S.U.

6)*

10:00 a.m.

Education Building — Lecture Room “B”

National Jr. Horticulture Society

6 )*

10:00 a.m.

Education Building — Herbarium

Herbarium Committee Meeting

6)*

1:00 p.m.

Botanic Gardens House — Dining Room

Editorial Committee Meeting

6)*

1 : 20 p.m.

Education Building — Lecture Room “B”

General Botany — Mrs. Carol Steele

6)

6:00 p.m.

Education Building — Horticulture Hall

Sierra Club

6)*

7:00 p.m.

Education Building — Lecture Room “B”

House Plant Class — Dave Woodward

6)

7:00 p.m.

Education Building — Lecture Room “C”

Denver Audubon Society (Wildlife Workshop)

6)

7:30 p.m.

Education Building — Lecture Room “A”

Denver Bonsai Club (Planning Committee)

7)*

8:30 a.m.

Education Building — Horticulture Hall

Landscape Management Workshop —

3:30 p.m.

Dr. J. Feucht

7)*

1:00 p.m.

Education Building — Lecture Room “C”

Tropical Plants of the Conservatory — Mrs. P. Hayward

8)*

1:20 p.m.

Education Building — Lecture Room “B”

General Botany — Mrs. Carole Steele

8)*

7:00 p.m.

Education Building — Lecture Room “C”

Landscape Horticulture — Mr. A1 Rollinger

8)*

7:30 p.m.

Education Building — Lecture Room “A”

Hobby Greenhouse Management — Mr. Robert Briggs

8)

7:30 p.m.

Education Building — Lecture Room “B”

Colorado Open Space Council

8)

7:45 p.m.

Education Building — Horticulture Hall

Denver Orchid Society

10)

9:00 a.m.

Library

Use of the Library

10)*

10:00 a.m.

Education Building — Lecture Room “A”

African Violet Show — Committee Chm.

10)

1:00 p.m.

Education Building — Lecture Room “B”

Colorado Organic Grower’s & Marketer’s Association

10)

1:30 p.m.

Education Building — Lecture Room “C”

“Voyage to the Enchanted Isles” — Free Film

♦ ♦♦♦♦♦♦♦

♦ ♦

12)*

4:00 p.m.

Education Building — Lecture Room “B”

Intensive Course in Botany — Dr. Miriam Denham

12)

7:30 p.m.

Education Building — Horticulture Hall

Colorado Mycological Society

12)

7:30 p.m.

Botanic Gardens House — Main Room

Sierra Club (Wildlife Workshop)

13)*

9:30 a.m.

Education Building — Lecture Room “B”

Civic Garden Club — Division “C”

13)*

1:20 p.m.

Education Building — Lecture Room “B”

General Botany — Mrs. Carol Steele

13)*

4:00 p.m.

Botanic Gardens House — Dining Room

Executive Committee Meeting

13)

6:00 p.m.

Education Building — Horticulture Hall

Sierra Club

13)*

7:00 p.m.

Education Building — Lecture Room “B”

House Plant Class — Dave Woodward

13)*

7:30 p.m.

Education Building — Lecture Room “A”

Swingle Study Group

14)*

10:00 a.m.

Education Building — Lecture Room “A”

Vegetable Gardening

14)*

1:00 p.m.

Education Building — Lecture Room “C”

Tropical Plants of the Conservatory — Mrs. P. Hayward

14)*

7:30 p.m.

Education Building — Lecture Room “A”

African Violet Pre-Convention Committee

14)*

7:30 p.m.

Botanic Gardens House — Dining Room

Landscape Industry Council

15)*

1:20 p.m.

Education Building — Lecture Room “B”

General Botany — Mrs. Carol Steele

15)*

7:00 p.m.

Education Building — Lecture Room “C”

Landscape Horticulture — Mr. A1 Rollinger

15)*

7:30 p.m.

Education Building — Lecture Room “A”

Hobby Greenhouse Management — Mr. Robert Briggs

15)

7:30 p.m.

Education Building — Lecture Room “B”

Organic Garden Club

16)

7:30 p.m.

Education Building — Lecture Room “C”

Denver Botany Club

17)*

9:30 a.m.

Education Building — Lecture Room “B”

Hi-Country Judges Workshop —

African Violet Judging Committee

17)

10:00 a.m.

Parking Lot, 909 York

Evergreen Walk

♦ ♦♦♦♦♦♦♦

♦ ♦

19)*

Noon

Botanic Gardens House - Dining Room

Colorado Garden Show, Inc.

19)*

4:00 p.m.

Education Building — Lecture Room “B”

Intensive Course in Botany — Dr. Miriam Denham

19)*

7:00 p.m.

Education Building - Lecture Room “B”

Dried Flower Arrangement — Mrs. Robt. Kosanke

20)

12:30 p.m.

Botanic Gardens House —

Rocky Mountain African Violet Council

Main - Dining - Kitchen

20)*

1:20 p.m.

Education Building — Lecture Room “B”

General Botany — Mrs. Carol Steele

20)*

7:00 p.m.

Education Building — Lecture Room “A”

House Plant Class — Dave Woodward

20)*

7:00 p.m.

Education Building — Lecture Room “C”

“Cadet Troops” — Irene Vittetoe

CALENDAR OF EVENTS FOR JANUARY (Continued)

20)

7:30 p.m.

Education Building — Horticulture Hall

20)

7:30 p.m.

Education Building — Lecture Room “B”

21)*

10:00 a.m.

Education Building — Lecture Room “A”

21)*

1:00 p.m.

Education Building — Lecture Room “C”

21)

7:30 p.m.

Education Building — Horticulture Hall

21)

7:30 p.m.

Education Building — Lecture Room “B”

22)*

9:00 a.m.

Education Building — Lecture Room “C”

22)*

10:00 a.m.

Botanic Gardens House — Main Room

22)*

1:20 p.m.

Education Building — Lecture Room “B”

22)*

7:00 p.m.

Education Building — Lecture Room “C”

22)*

7:30 p.m.

Education Building — Lecture Room “A”

22)

7:30 p.m.

Education Building — Lecture Room “B”

22)*

7:30 p.m.

Botanic Gardens House —

Main - Dining - Kitchen

23)*

10:00 a.m.

Education Building — Horticulture Hall

24)

9:30 a.m.

Education Building — Lecture Room “A”

26)*

9:30 a.m.

Botanic Gardens House — Main Room

26)*

1:00 p.m.

Botanic Gardens House — Dining Room

26)*

4:00 p.m.

Education Building — Lecture Room “B”

26)*

7:00 p.m.

Education Building — Lecture Room “B”

26)

8:00 p.m.

Education Building — Horticulture Hall

27)*

1 :20 p.m.

Education Building — Lecture Room “B”

27)*

4:00 p.m.

Botanic Gardens House — Conference Room

27)

7:30 p.m.

Education Building — Lecture Room “C”

to

00

*

10:00 a.m.

Education Building — Lecture Room “A”

28)*

1 :00 p.m.

Education Building — Lecture Room “A”

28)*

1:00 p.m.

Education Building — Lecture Room “C”

28)

7:30 p.m.

Education Building — Lecture Room “C”

29)*

1 :00 p.m.

Botanic Gardens House — Main Room

29)*

1 :20 p.m.

Education Building — Lecture Room “B”

29)*

7:00 p.m.

Education Building — Lecture Room “C”

29)*

7:30 p.m.

Education Building — Lecture Room “A”

30)*

10:00 a.m.

Education Building — Horticulture Hall

31)

9:30 a.m.

Education Building — Lecture Room “C”

J

♦ ♦♦♦♦♦♦

FEBRUARY

2)*

4:00 p.m.

Education Building — Lecture Room “B”

2)*

7:00 p.m.

Education Building — Lecture Room “B”

3)*

9:00 a.m.
5:00 p.m.

Education Building — Lecture Room “C”

3)*

10:00 a.m.

Education Building — Herbarium

3)*

1:00 p.m.

Botanic Gardens House — Dining Room

3)*

1:20 p.m.

Education Building — Lecture Room “B”

3)*

7:00 p.m.

Education Building — Lecture Room “A”

3)

7:00 p.m.

Education Building — Lecture Room “C”

3)

7:30 p.m.

Education Building — Lecture Room “B”

4)*

8:30 a.m.

Education Building — Horticulture Hall

4)*

10:00 a.m.

Education Building — Lecture Room “A”

4)*

10:00 a.m.

Botanic Gardens House — Main Room

4)*

1:00 p.m.

Education Building — Lecture Room “A”

4)*

1:00 p.m.

Education Building — Lecture Room “C”

4)*

7:00 p.m.

Education Building — Lecture Room “C”

5)*

9:00 a.m.

Botanic Gardens House — Main Room

5)*

1 :20 p.m.

Education Building — Lecture Room “B”

5)*

7:00 p.m.

Education Building — Lecture Room “C”

5)*

7:30 p.m.

Education Building — Lecture Room “A”

5)

7:30 p.m.

Education Building — Lecture Room “B”

5)*

7:45 p.m.

Education Building — Horticulture Hall

*Members or enrollees only

Sierra Club

Denver Bonsai Club

Vegetable Gardening — Larry Latta

Tropical Plants of the Conservatory — Mrs. P. Hayward

Plan Metro Denver

Colorado Open Space Council (Air Quality Workshop)

African Violet Society of Denver

Around the Seasons

General Botany — Mrs. Carol Steele

Landscape Horticulture — Mr. A1 Rollinger

Hobby Greenhouse Management — Mr. Robert Briggs

Sierra Club (Oil Shale)

Denver Men’s Garden Club

Ikebana International

Soils & Plant Growth Relations — Dr. James Jackson

•*

African Violet Councel (Formation of new group)

Associates Board Meeting

Intensive Course in Botany — Dr. Miriam Denham
Dried Flower Arrangements — Mrs. Robt. Kosanke
“Rhododendron’s & Azalea’s in Denver — Why Not?”

Dr. Walter Eickhorst
General Botany — Mrs. Carol Steele
Board of Trustees Meeting
Gladiolus Society

Vegetable Gardening — Larry Latta
History of Botany — Dr. Margaret Goodhue
Tropical Plants of the Conservatory — Mrs. P. Hayward
Colorado Open Space Council (Wilderness Workshop)

Guides Social

General Botany — Mrs. Carol Steele
Landscape Horticulture — Mr. A1 Rollinger
Hobby Greenhouse Management — Mr. Robert Briggs
Ikebana International (Workshop)

Solar Energy Greenhouses — Mr. James Wiegand

♦ ♦

Intensive Course in Botany — Dr. Miriam Denham
Dried Flower Arrangements — Mrs. Robert Kosanke
Master Gardeners — Dr.J.Feucht

Herbarium Committee Meeting

Editorial Committee Meeting

General Botany — Mrs. Carol Steele

“Cadet Troops” — Irene Vitte toe

Denver Audubon Society (Wildlife Workshop—

Denver Bonsai Club

Landscape Management Workshop — Dr.J.Feucht

Vegetable Gardening — Larry Latta

Plant Sale Meeting — Mrs. H. Franson

History of Botany — Dr. Margaret Goodhue

Tropical Plants of the Conservatory — Mrs. P. Hayward

Vegetable Gardening — Community College — Mr. Lee Ashley

Master Gardeners — Dr.J.Feucht

General Botany — Mrs. Carol Steele

Landscape Horticulture — Mr. A1 Rollinger

Hobby Greenhouse Management (Advanced) - Mr. Robert Briggs

Colorado Open Space Council

Denver Orchid Society

PLANT PORTRAITS

Fifty paintings by Ida Hrubresky Pemberton, on loan
from the University of Colorado Museum, will be shown in
the herbarium display area from January 7 to January 31.

Mrs. Pemberton was born in Nebraska in 1890 and
studied at the Art Institute of Chicago. She sent for bulbs,
roots and seeds of medicinal plants, grew them in her own
greenhouse, and then painted each stage of the plants’
development. Each of the plates shows the growth habit of
the mature plant and, since Mrs. Pemberton often used a
microscope for detail work, are extremely accurate botanical
drawings.

Twenty-five will be displayed for two weeks and then
twenty-five more will be hung. The hostess/information desk
volunteers will be on hand from 10 AM to 3 PM daily. It is
hoped that many of our members will come view this
fascinating exhibit of watercolors.

January Classes

Reminder: General Botany for Non-Majors will be
taught on Tuesday and Thursday from January 6 to March
1 1. The times are 1:20 - 2:50 PM, Tuesdays and 1 :20 -5:10
PM Thursdays, Classroom B. Call 292-5190 Ext. 246 for
information on college credit or 297-2547 for information
on cost for non-credit work. Limit 15.

The following
Training Class and
requests.

Carol Andrews
Debbie Clark
Mary A. Clark
Kathryn Deegan
Phil Eddings
Ed Eisler
Tina Jones

students have completed the fall Guides
will soon start helping meet the tour

Gladys Kirk
Margo Kraettli
Dan Kruse
Sophie Lo
Marian E. Martin
Lora Morris
Paula Ogilvie

Jan Osgood-Mihal
Mary Payson
John P. Pursell
Betty Silver
Kit Spahn
Beth Ann Travis
Virginia Valentine

Would you like to help with this worthwhile effort of
the Volunteers? Join the new class now! Tropical Plants of
the Conservatory is listed for January 7 - March 10, 1-3
PM, Classroom C and Conservatory. The cost is $25.00 to be
refunded if the student guides for a total of 40 hours.

Landscape Horticulture is offered on Thursday evenings
from January 8 - February 26, 7 to 9:30 PM, Classroom C.
Mr. E. Alan Rollinger and Mr. Larry Watson, both well
known authorities for this area, will explain many points to
remember when creating a desirable outdoor living space.
The cost is $15.00 for members and $20.00 for non¬
members.

Beginning Hobby Greenhouse Management is full, but
currently the advanced class in February still has a few
spaces.

Ms. Huggins will teach Use of the Library on Saturday,
January 10 at 9:00 AM in the Library. This class will
provide a free opportunity to enhance your skill in the use
of this most important section of the Gardens.

Vegetable Gardening is always a popular course. Larry
Latta, who offered such a well received one in the fall, will
continue with many helpful ideas to make things easier in
the planting season. This class will be taught on Wednesday,
January 14 - February 11 from 10 AM to Noon, Classroom
A. Cost $10.00 for members, $15.00 for non-members.

The Director of the Gardens, Dr. William Gambill, will
lead a Tree Walk in Cheesman Park to study evergreens on
January 17. Meet at 10 AM at 909 York Street. Bundle up
and bring your interest and enthusiasm. Free.

An opportunity to make one-of-a-kind arrangements for
the perfect house warming gift is scheduled for January 19
to February 9. Avalonne Kosanke will teach Dried Flower
Arrangement from 7 to 9:30 PM, Classroom B. The cost is

$12.50 for members and $17.50 for non-members. This

■ • > •->

includes the cost of the materials to be used.

Dr. James Jackson will discuss Soil and Plant Growth
Relations at 9:30 AM, January 24 in Classroom A. His
outline covers such topics as houseplant soil - formulas,
sterile soil preparation, desired soil for certain plants; garden
soil with emphasis on Denver County soil survey — what a
soil analysis shows and where to get one done, and soil
additives. Free.

Theophrastus, who was born about 373 B.C., is
generally regarded as the father of botany. He studied at the
Academy in Athens with Plato and when Aristotle founded
the Lyceum, Theophrastus joined him and later became its
head. Not only did he write An Enquiry Into Plants, a
scientific work which is the first known attempt to classify
plants, he also was a keen gardener. In his garden were
grown many plants of which he wrote and in his will he
made arrangements for the maintenance of his garden after
his death.

Information like the above and much more can be
learned in History of Botany. Dr. Goodhue will offer this
class starting on January 28 to March 3 from 1 to 3 PM,
Classroom A. The fee is $15.00 for members and $20.00 for
non-members. Limit 30.

Finally a class which speaks to a topical interest is Solar
Energy Greenhouses. Come to Classroom C at 9:30 AM on
January 31 for this lecture. Free.

*********

On January 10 join us on a Voyage to the Enchanted
Isles. This color film visits the Galapagos Islands where
Charles Darwin on HJM.S. Beagle obtained insights for his
famous theory on the origin of the species. As the narrator
quotes from Darwin’s Journals, magnificent photography
records strange and fascinating sights that are relatively
unchanged since Darwin’s time. Classroom C, 1:30 PM. Free.
*********

Closer to home, the first crocus, ‘E. P. Bowles’, was
noticed last year on January 15. (In fact it may have been
blooming earlier but none of us thought to look for it.)
Keep your eyes open when you visit the Denver Botanic
Gardens and help us spot the earliest flower this year.

CENTENNIAL TAPESTRY

A Colorado Centennial Tapestry, designed and worked
by Opportunity School students, which features such sights
as Larimer Square, the Capitol and the Denver Botanic
Gardens will be on display at the Denver Art Museum until
January 6. Approximately 70 students ranging in age from
24 to 75 worked for 7 months on this project; one of our
tour guides, Helen Clifford, did the block of the Gardens. It
is estimated that it took 40 hours to complete each of the
76 pieces which go to make up the final 6 by 9 foot
sampler.

Free Lecture

Mr. Walter Eickhorst, Curator of Cultivated Plants at the
Morton Arboretum in Lisle, Illinois, is scheduled to speak at
the Denver Botanic Gardens on January 26th.

His illustrated lecture will be based on his successful
experience in growing rhododendrons in Illinois and is titled
“Rhododendrons and Azaleas in Denver — Why Not?”

The public lecture, open to all, will be at 8 p.m. in
Horticulture Hall, 1005 York.

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cuttings into the sand and loosely tie the top. Put the bags
in a place that will be away from direct sunlight until
rooted. (Roots will be visible on the inside of the plastic
bags.)

I have found that the largest “zip-loc” type bags make
good rooting chambers. They can be “zipped up” in the
center, leaving vents at each end of about one-half inch.
Venting is needed to reduce sweating inside the bag which
may result in rotting of both foliage and stems.

Once the cuttings have rooted, carefully remove them
from the bags (cutting bags open rather than trying to save
them is usually safer) and pot them in four-inch pots.

Happy gardening in ’76!

Dr. J. R. Feucht

Colorado State University, through its County Extension
Services, is offering a program to fill the tremendous need
for providing information to the gardening public.

The endeavor is a volunteer effort called the Master
Gardener Program, and utilizes the talents of experienced,
knowledgeable gardeners who have a desire to share that
knowledge with others in the community.

Recruitment for volunteers will begin in January for
persons of any age, sex, or national background who have
gardening experience and have the time to devote a mini¬
mum of 36 daytime hours of public service.

All volunteers who are accepted will be trained by
Horticulturists from the Colorado State University Extension
Service in daytime sessions. Sessions will be offered every
Tuesday and Thursday through the month of February in
Denver and Berthoud. Colorado Springs and Pueblo training
sessions will be held every Wednesday and Friday during
February and early March.

Interested persons should request an application form, as
soon as possible, from your nearest County office or from
the Denver Botanic Gardens, 297-2547.

Introducing Dr. Pat Smith

Members will have noticed a new name on the last issue
of The Green Thumb magazine, for we have a new Editor!
Pat has a Masters degree in English and PhJD. in Communi¬
cations. For the past three and a half years, she has been
editing the technical and popular journals of the Society for
Range Management here in Denver. Welcome.

Visit the Athens of the North

By now, all will have received information about the
trip to Great Britain. Did you know the Royal Botanic
Garden in Edinburgh is the second oldest in the United
Kingdom? Two eminent medical men started a small garden
near Holyrood Palace in 1670. It was approximately 40 x 40
feet and was used to grow medicinal plants. After several
expansions and moves, the Royal Botanic Garden was estab¬
lished at its present site, 70 acres at Inverleith, in 1820.

Not only is it a sanctuary from the hustle and bustle of
the city and a mecca for gardening enthusiasts with one of
the finest rock gardens and the largest collection of Rhodo¬
dendrons in cultivation in the world, but is also a center of
scientific research. The Herbarium includes two million dried
specimens. Ail this plus the excitement of being in Edin¬
burgh with its history of Mary, Queen of Scots and Bonnie
Prince Charlie.

Don’t delay in signing up for the trip — May 23 to June
13, 1976.

Help please!

We need a volunteer to help one-half day a week
transcribing plant propagation worksheet information to file
cards. It would be especially helpful if the person is a good
typist.

If you are interested, please call Lee Schwade,
297-2547.

Green Thumb Newsletter is published monthly by Denver Botanic Gardens,
Inc., 909 York Street, Denver, Colorado 80206. The Newsletter is included as a
benefit of membership in the Denver Botanic Gardens, regular membership dues
being $10.00 a year. Items for publication are welcome. The deadline for copy
to the editor is 2:00 p.m. on the 10th of each month preceding publication.
Editor — Margaret Sikes, 297-2547, Ext. 23.

(ffi6l)lhufllb Newsletter DENVER botanic gardens, inc.

Copyright 1976

NUMBER 76-3 MARCH 1976 TELEPHONE 297-2547

GARDENING TIPS FOR MARCH

Recently, Mr. Larry Gueck, Extension Horticulturist,
Jefferson County, and I completed .a “tour” of the east
slope from Pueblo to Greeley, presenting some workshops on
transplanting and pruning practices. One question seemed to
crop up at each location that, at least in my mind, seemed
the most misunderstood of all and is worth elaborating on in
this column. The question, “What is sunscald and how does
it come about”? A fairly universal answer from the audience
was that is “burn from the sun”: a seemingly logical answer
based upon the term sunscald. The term ‘sunscald’ is really
very unfortunate since it does convey an idea that the sun
causes a burn or scald. This, however, could not be further
from the truth. Let’s look at what really happens.

To understand sunscald, it would be well to first review
the hardening-off and dormancy cycle of a hardy, woody
plant because this has bearing on the subject. In late summer
and on into the fall months, woody plants go into successive
stages of “hardening” or getting ready for winter. This is
triggered primarily by shortening days and cooling
temperatures but can also be hastened by stress from
temporary water deficits. During this process, the complex
chemistry of a plant changes and gradually, the free water in
the plant cells becomes “chemically bound”, resulting in
cells and tissues that can freeze without killing them. Most
plants are not in a full dormancy until late into the fall. This
dormancy brings about a certain amount of stability in the
plant that is not affected by external climatic changes until
the plant has experienced a given amount of cold. In other
words, the plant is in an irreversible state of dormancy until
the cold period has been satisfied. This period varies from
one plant to another but as a general rule, plants begin to
reverse (come out of the dormant state) about mid-January.
It is at this time and on into early spring that a thin-barked
tree may be subject to sunscald.

At that time of year (January-April) it is common to
have warm, sunny shirt-sleeve days but usual to have rapid
drops in temperature at night. The angle of the sun is also
low. As the sun warms the side of a thin-barked tree (the
southwest side) cells in the bark tissues become active much
as they would be in May or June. The bound water becomes
free water. At night, the cells are killed when the tempera¬
tures drop rapidly. The rapid drop causes the free water in
the cells to move into the intercellular spaces, thus dehy¬
drating the cell contents. Thus, sunscald is really a
dehydration process just as any other type of winterkill or
freeze damage is. It is not the result of ice crystals
puncturing the cell walls as was once thought.

Trees are wrapped to insulate against sudden tempera¬
ture change. In other words, it keeps the plant consistently
cold. The commercial “crepe” tree wraps are designed for
this purpose, containing both insulating material and a light,
reflective surface.

What trees need to be wrapped? Any fall-transplanted,
thin-barked tree should be, particularly, if it is shy of many
limbs to shade the trunk and if it is going to be planted in
an exposed situation. Large trees which have thin bark
should be wrapped for at least two winters. Young honey-
locust, redbud, green ash, maple and mountain ash, among
others, are particularly vulnerable. Hackberry, oaks, aspen

and white birch seem to be less prone. The latter two
probably because they already have a light, reflective bark.

Where practical, tree wraps should be removed during
the growing season and replaced in the fall. There have been
some cases where the wrap itself harbored injurious insects
and diseases.

Wrapping from the bottom up to the first or second
scaffold branch is desirable. In this way, water sheds off the
wrap reducing conditions for disease development and ice
formation.

To hold the final twist of the wrap at the top, use a
single tack or a tacker gun. Avoid tape, wire, or string that
may eventually cause a girdling of the trunk.

As indicated in last month’s column, now would be a
good time to start some of the garden flowers indoors but
only start those that are slow to develop. If started too
early, they will tend to become “leggy” and may require
supplemental light. About the middle of the month you
could plan to start some of the smaller seeds like petunia,
verbena, seed geraniums, ageratum, and coleus. Other more
common annuals like marigold and zinnias should await
mid-April because they germinate quickly and will soon
outgrow the pots before they can be put out in mid-May.

It is best to use sterilized soil, making sure that the soil
is well drained. If you use the potting mixes available in
grocery stores and garden centers, mix it with some of your
own soil. Most potting soils are too high in organic matter,
tending to become either too wet or too dry. To sterilize the
soil, place it in your oven in shallow pans at a temperature
not to exceed 250 degrees for 45 minutes.

Most any container for planting will do but it should
have drainage holes near the bottom on the sides. By the
way, you will need some kind of saucer underneath the pot
in order to catch excess moisture. To keep seed moist until
germination, they can be covered with plastic or kept under
glass. Once germination starts, the cover must be removed
and the pots gradually placed in a bright exposure.

To prevent damping-off, a serious disease of seedlings
even though the soil has been sterilized, it is a good idea to
pretreat the seeds with a small amount of fungicide such as
“Maneb” or “Captan”. The easiest way to treat the seeds is
to cut the seed packet at one corner, then use enough of the
powdered fungicide to cover the tip of a knife. Place it in
the seed packet and shake the seed up until it is fully coated
with the fungicide.

On warm days in March it is a good idea to do a little
pruning around the yard particularly some of the deciduous
shrubs that have become too leggy and crowded with large
canes. Lilacs, honeysuckle and some of the viburnums
eventually develop a thicket of canes that should be thinned
to keep the plant healthy as well as attractive. The dormant
period is a good time because it is easier to work in the
plant and you can often destroy a lot of the insect problems
such as oyster shell scale and borers. Usually the older canes
are the weaker and are subject to more scale and borer
problems. This is particularly true of lilacs. Most canes
should be removed as close to the ground as possible. This
will require curved pruning shears and a good pair of lopping
shears. By properly thinning and spacing the canes to allow
more light to penetrate, the shrub will develop a better
foliage, thus making the plant healthier, as well as prettier.

-Dr. J. R. Feucht

SILVER ANNIVERSARY
OF THE DENVER BOTANIC GARDENS

DeBOER MEMORIAL TREE FUND

The first meeting of the Board of Trustees of the
Botanic Gardens Foundation of Denver, Inc. was on
February 27, 1951, although the Corporation became official
when the Articles of Incorporation was authorized on
February 3, 1951.

The first meeting was held in the beautiful home of Mr.
& Mrs. John Evans which was then on East Alameda Avenue
at York Street. The charter Trustees were Mrs. A. L.
Barbour, Mr. Myron Blackmer, Mr. S. R. DeBoer, Mrs. John
Evans, Mr. William H. Ferguson, Mrs. George H. Garrey, Mr.
Milton J. Keegan, Mr. George Kelly, Mr. Robert E. More, Dr.
Moras L. Shubert, Dr. Robert L. Stearns and Mrs. James J.
Waring. Ex-Officio members were Mr. Frazer Arnold, Presi¬
dent, Denver Zoological Foundation; Mr. Fred R. Johnson,
President, Colorado Forestry & Horticulture Association; Mr.
Hudson Moore, Jr., President, Museum of Natural History;
and Mayor Quigg Newton.

Those present at the first meeting were Mrs. A. L.
Barbour, Mr. Myron Blackmer, Mr. S. R. DeBoer, Mrs. John
Evans, Mrs. George H. Garrey, Mr. Milton J. Keegan, Mr.
George Kelly, Mr. Robert E. More, Dr. Moras L. Shubert,
Mrs. James J. Waring, Mr. Frazer Arnold, Mr. Fred R.
Johnson and Mr. Hudson Moore, Jr.

The principal business of the meeting involved adopting
the By-Laws, ratification of our Agreement with the City &
County of Denver, adoption of the official seal and election
of officers. Elected were:

Mrs. John Evans, President
Mr. Milton J. Keegan, Vice-President
Mr. Malcolm Lindsey, Vice-President
Mrs. George H. Garrey, Vice-President
Dr. Moras L. Shubert, Secretary-Treasurer

Executive Committee Members:

Officers listed above, and
Mr. Myron K. Blackmer
Mr. S. R. DeBoer
Mr. William H. Ferguson
Mr. Hudson Moore, Jr.

Five of the present Trustees are charter members: Mrs.
George H. Garrey, Mr. Hudson Moore, Jr., Dr. Moras L.
Shubert, Dr. Robert L. Stearns, Mrs. James J. Waring.

The first attempt to establish a Botanic Gardens area in
City Park proved unsuccessful because of theft and
vandalism so the York Street site was acquired and through
the generosity of Mrs. Waring, so was the present Botanic
Gardens House.

During the last 25 years much has been achieved and
the accomplishments have been accelerating in recent years.
May the next 25 years be as productive and rewarding.

Residents of the City and County of Denver are invited
to participate in a tree planting program co-sponsored by the
City & County of Denver, Trees for Today and Tomorrow,
and The Park People. This project provides a $20.00
incentive to be paid to the property owner to help defray
the cost of one tree per property per year. The tree must
cost $40.00 (or more), must be planted in the curb area
(public right-of-way, between the curb and property line),
and must be chosen and planted according to the Denver
City Forester’s specifications.

To learn more about the Denver Street Tree Planting
Project, contact the City Forester at 297-2571 or Trees for
Today & Tomorrow, Ken Hostetler, 355-1405.

The Colorado Chapter of the American Society of Land¬
scape Architects has established a fund for the planting of
groves of trees in DeBoer Park, located at Harvard Ave. and
South Vine Street, Denver.

S. R. DeBoer, a Fellow of A.S.L.A., was the Landscape
Architect for the City of Denver from 1910-1931, and
became its planning engineer and park consultant from 1932
until 1958. He was in private practice until his passing, in
1974, at the age of 91.

His foresight and ability in designing and planting our
parks, parkways and Civic Center, have given the citizens of
Denver a great heritage of beauty.

One of his last wise comments: “Before it is too late, we
must not stop in our planning for beauty. Our trees and
parks and gardens must be renewed constantly if we are to
leave a decent world for those who follow us. Now is the
time to plan that world!”

If you appreciate this great inheritance, would you care
to honor him? Your tax deductible contribution made
payable to The Park People for DeBoer Memorial Tree Fund
should be mailed to Eugene Field House, 715 South
Franklin Street, Denver, Colorado 80209.

For the remarkable impact of S. R. DeBoer, on the city of
Denver, refer to The Green Thumb, December 1972.

The North-Central Branch of the Entomological Society
of America will hold its 1976 meeting at the Hilton Hotel
on March 24, 25 and 26th. These meetings will interest
scientists, educators, insect hobbyists, and various chemical
leaders.

For further information, please contact John A. Quist,
Colorado State University, 221-1186.

The lectures at the Federation Garden Club Head¬
quarters, 1556 Emerson St., will continue on March 31 with
two speakers at 9:30 and 11:30 A.M. Mario Meakins will
speak on Composting and Mulching and Selection and
Planting of Trees will be discussed by Jim Feucht. The cost
is 50<t for members and $ 1 .00 for non-members. Please pay
at the door.

DENVER BOTANIC GARDENS
CALENDAR OF EVENTS
MARCH, 1976

MARCH

1)

10:00 a.m.

Education Building - Lecture Room “A”

2)*

9:00 a.m.

Education Building — Lecture Room “C”

2)*

10:00 a.m.

Education Building — Herbarium

2)*

1 :00 p.m.

Botanic Gardens House — Dining Room

2)*

1:20 p.m.

Education Building — Lecture Room “B”

2)

7;00 p.m.

Education Building — Lecture Room “C”

2)

7:30 p.m.

Education Building — Lecture Room “B”

3)*

10:00 a.m.

Education Building — Lecture Room “A”

3)*

1:00 p.m.

Education Building — Lecture Room “C”

3)*

7:00 p.m.

Education Building — Lecture Room “C”

3)*

7:00 p.m.

Education Building — Lecture Room “B”

3)

7:30 p.m.

Education Building — Horticulture Hall

3)

7:30 p.m.

Education Building — Lecture Room “A”

4)*

1 :20 p.m.

Education Building — Lecture Room “B”

4)

7:30 p.m.

Education Building — Lecture Room “C”

4)*

7:45 p.m.

Education Building — Horticulture Hall

5)

11:00 a.m.

Botanic Gardens House —

Main - Dining - Kitchen

6)

9:30 a.m.

Botanic Gardens House — Main Room

6)

9:30 a.m.

Education Building — Lecture Room “A”

7)*

3:00 p.m.

Education Building — Lecture Room “C”

♦ ♦♦♦♦♦♦

8)*

10:00 a.m.

Education Building — Lecture Room “A”

8)*

11:30 a.m.

Botanic Gardens House

Main - Dining - Kitchen

8)*

7:00 p.m.

Education Building — Lecture Room “A”

8)*

7:00 p.m.

Education Building — Lecture Room “B”

8)

7:30 p.m.

Education Building — Horticulture Hall

8)

7:30 p.m.

Botanic Gardens House — Main Room

9)*

9:30 a.m.

Education Building — Lecture Room “A”

9)

9:30 a.m.

Education Building — Lecture Room “C”

9)*

10:00 a.m.

Education Building — Lecture Room “B”

9)*

1:20 p.m.

Education Building — Lecture Room “B”

9)*

4:00 p.m.

Botanic Gardens House — Dining Room

9)*

7:00 p.m.

Education Building — Lecture Room “C”

9)

7:30 p.m.

Education Building — Horticulture Hall

10)*

9:15 a.m.

Botanic Gardens House —

Main - Dining - Kitchen

10)*

1:00 p.m.

Education Building — Lecture Room “C”

10)*

7:00 p.m.

Education Building — Lecture Room “B”

10)*

ID

7:30 p.m.

Botanic Gardens House — Dining Room
GARDENS CLOSED AT NOON

11)*

1:20 p.m.

Education Building — Lecture Room “B”

11)*

7:00 p.m.

Education Building — Horticulture Hall

11)

7:30 p.m.

Botanic Gardens House

Main - Dining - Kitchen

12)

7:30 p.m.

Botanic Gardens House —

Main - Dining - Kitchen

13)

9:00 a.m.

Education Building — Horticulture Hall

13)

1 :00 p.m.

Education Building — Lecture Room “B”

13)

1:30 p.m.

Education Building — Lecture Room “C”

15)*

10:00 a.m.

Education Building — Lecture Room “A”

15)*

7:00 p.m.

Education Building — Lecture Room “A”

15)*

7:00 p.m.

Education Building — Lecture Room “B”

16)*

10:00 a.m.

Education Building — Lecture Room “B”

16)

12:30 p.m.

Botanic Gardens House —

Main - Dining Kitchen

♦ ♦♦♦♦♦♦

National Jr. Horticulture
Master Gardeners
Herbarium Committee Meeting
Editorial Committee Meeting
General Botany — Mrs. Carol Steele
Denver Audubon Society
Denver Bonsai Club

Vegetable Gardening — Mr. Larry Latta
Tropical Plants of the Conservatory — Mrs. P. Hayward
Vegetable Gardening — Mr. Lee Ashley
House Plant Class — Mr. Dave Woodward
(Call Denver Free Univ. — 832-6688)

Mycological Workshop — Mr. George Grimes
Sierra Club

General Botany — Mrs. Carol Steele
Colorado Open Space Council
Denver Orchid Society
Civic Garden Club

Gloxinia Gesneriad Growers

National Jr. Horticulture

African Violet Council — Education Seminar

♦ ♦♦♦♦♦♦

Vegetable Gardening — Mr. Dick Hannigan
Rocky Mtn. Belles African Violet Club

Vegetable Gardening — Mr. Dick Hannigan
(Call Community College — 861-9888)

Basic Bonsai — Mrs. Mary Neil
Colorado Mycological Society
Denver Sierra Club (Wildlife Committee)

Civic Garden Club — Division “C”

Basic Taxonomy — Dr. Helen Zeiner
Basic Bonsai — Mrs. Mary Neil
General Botany — Mrs. Carol Steele
Executive Committee Meeting
Vegetable Gardening — Mr. Dick Hannigan
Mycological Workshop — Mr. George Grimes
D.B.G. Guild Meeting

Tropical Plants of the Conservatory — Mrs. P. Hayward
House Plant Class — Mr. Dave Woodward
Landscape Industry Council

General Botany — Mrs. Carol Steele

Annual Membership Dinner — Social Hour 6:00-7:00 p.m.

Denver Rose Society

Denver Dahlia Society

Rose Symposium

Colorado Organic Grower’s & Marketer’s Association
Film: “World of Roses”

Vegetable Gardening — Mr. Dick Hannigan
Vegetable Gardening — Mr. Dick Hannigan
Basic Bonsai — Mrs. Mary Neil
Basic Bonsai — Mrs. Mary Neil
Rocky Mtn. African Violet Council

♦ ♦♦♦♦♦♦

CALENDAR OF EVENTS FOR THE MONTH OF MARCH (Continued)

16)*

7:00 p.m.

Education Building — Lecture Room “C”

16)

7:30 p.m.

Education Building — Horticulture Hall

16)

7:30 p.m.

Education Building — Lecture Room “B”

17)

9:00 a.m.

Botanic Gardens House — Parking Lot

17)

10:00 a.m.

Education Building — Lecture Room “A”

17)*

7:00 p.m.

Education Building — Lecture Room “B”

17)*

7:00 p.m.

Education Building — Lecture Room “A”

17)

7:30 p.m.

Education Building — Horticulture Hall

17)

7:30 p.m.

Education Building — Lecture Room “C”

18)

7:30 p.m.

Education Building — Lecture Room “A”

18)*

7:30 p.m.

Education Building — Lecture Room “B”

18)

7:30 p.m.

Education Building — Lecture Room “C”

19)*

4:00 p.m.

Botanic Gardens House —

19)

7:30 p.m.

Main - Dining — Kitchen

Education Building — Lecture Room “C”

20)

9:30 a.m.

Education Building — Lecture Room “A”

20)

9:30 a.m.

Education Budding — Lecture Room “B”

20)

9:30 a.m.

Education Building — Lecture Room “C”

22)*

10:00 a.m.

♦ ♦♦♦♦♦♦

Education Building — Lecture Room “A”

22)*

7:00 p.m.

Education Budding — Lecture Room “A”

22)*

7:00 p.m.

Education Budding — Lecture Room “B”

23)*

10:00 a.m.

Education Budding — Lecture Room “B”

23)*

4:00 p.m.

Botanic Gardens House — Conference Room

23)*

7:00 p.m.

Education Budding — Lecture Room “A”

23)

7:30 p.m.

Education Budding — Lecture Room “C”

23)

8:00 p.m.

Botanic Gardens House — Main Room

23)

8:00 p.m.

Education Building — Horticulture Hall

24)*

7:00 p.m.

Education Budding — Lecture Room “B”

24)

7:30 p.m.

Education Building — Lecture Room “A”

25)*

10:00 a.m.

Botanic Gardens House — Main Room

25)*

10:00 a.m.

Education Budding — Lecture Room; “A”

25)*

1 1:00 a.m.

Education Budding — Lecture Rooms “B”

&

25)*

7:30 p.m.

Botanic Gardens House —

26)*

8:00 a.m.

Main - Dining - Kitchen

Education Budding — Lecture Rooms “B”

&

26)*

10:00 a.m.

Education Building — Horticulture Hall

27)

10:00 a.m.

Education Budding — Lecture Room “A”

27)*

1:00 p.m.

Education Building — Lecture Room “C”

29)*

10:00 a.m.

♦ ♦♦♦♦♦♦

Education Building — Lecture Room “A”

29)*

7:00 p.m.

Education Budding — Lecture Room “A”

29)*

7:00 p.m.

Education Building — Lecture Room “B”

29)

8:00 p.m.

Education Budding — Lecture Room “C”

30)*

10:00 a.m.

Education Building — Lecture Room “B”

30)*

7:00 p.m.

Education Building — Lecture Room “A”

31)*

1:00 p.m.

Botanic Gardens House —

31)*

7:00 p.m.

Main - Dining - Kitchen

Education Buddirtg — Lecture Room “B”

31)

7:30 p.m.

Education Building — Lecture Room “A”

31)

7:30 p.m.

Education Budding — Lecture Room “C”

APRIL

1)*

9:00 a.m.

♦ ♦♦♦♦♦♦

Education Building — Lecture Room “A”

1)

7:30 p.m.

Education Budding — Lecture Room “C”

1)*

7:45 p.m.

Education Budding — Horticulture Hall

2)*

9:00 a.m.

Education Building — Lecture Room “A”

2)

11:00 a.m.

Botanic Gardens House —

3)

9:00 a.m.

Main — Dining — Kitchen

Education Building — Horticulture Hall

3)*

9:00 a.m.

Education Building — Lecture Room “A”

3)

9:30 a.m.

Botanic Gardens House — Main Room

3)

1 :30 p.m.

Education Budding — Lecture Room “C”

Vegetable Gardening — Mr. Dick Hannigan
Sierra Club
Denver Bonsai Club

PLANT LIFE FIELD TRIP - Dr. E. H. Brunquist
“Identification of Shrubs” — Dr. James Feucht
Basic Flower Arrangement — Mr. Lee Ashley
House Plant Class — Mr. Dave Woodward
Mycological Workshop — Mr. George Grimes
Denver Comfnission on Community Relations
Colorado Open Space Council (Air Quality Workshop)

Colorado Bonsai Club
Organic Garden Club
“Leadership Denver ”

Denver Botany Club
National Jr. Horticulture
Hi-Country Judges Workshop
“Home Landscaping” — Barbara Hyde

♦ ♦♦♦♦♦♦

Vegetable Gardening — Mr. Dick Hannigan

Vegetable Gardening — Mr. Dick Hannigan

Basic Bonsai — Mrs. Mary Neil

Basic Bonsai — Mrs. Mary Neil

Board of Trustees Meeting

Vegetable Gardening — Mr. Dick Hannigan

Gladiolus Society

English Speaking Union — Speaker: Malcolm Booth
“Wildflowers of Northern Montana & Southern Alberta”
Speaker: Mr. Lou Hagener
Basic Flower Arrangement — Mr. Lee Ashley
Mycological Workshop
Around the Seasons Meeting
African Violet Club — Chapter 1

“C” U.S. Forest Service Workshop — “Endangered Plant Species”
Denver Men’s Garden Club

“C” U. S. Forest Service Workshop
Ikebana International

“Rose Pruning Demonstration” — Mrs. H. Franson & Mr. G. Park
African Violet Show Committee Chairmen

♦ ♦♦♦♦♦♦

Vegetable Gardening — Mr. Dick Hannigan

Vegetable Gardening — Mr. Dick Hannigan

Basic Bonsai — Mrs. Mary Neil

Nature Conservancy

Basic Bonsai — Mrs. Mary Neil

Vegetable Gardening — Mr. Dick Hannigan

Guides Social — Speaker: Mr. Jim Wright

Basic Flower Arrangement — Mr. Lee Ashley
Mycological Workshop

Colorado Open Space Council (Wilderness Workshop)

♦ ♦♦♦♦♦♦

“Keep Colorado Beautiful”

Colorado Open Space Council
Denver Orchid Society (Orchid Auction)

“Keep Colorado Beautiful”

Civic Garden Club

Gladiolus & Dahlia Bulb Sale
“Keep Colorado Beautiful”

Gloxinia Gesneriad Growers
Film: “Magic Carpet of Tulipland”

*MEMBERS OR ENROLLEES ONLY

SPRING CLASSES

By now members should have received the Spring List
of Classes and it is hoped all will find something of interest
listed therein.

Students wishing to learn more about horticulture are
urged to attend the March 6 Orientation to the National
Junior Horticulture Association programs and contests and
to return on March 20 to learn to identify Plants in Winter
Condition. Both sessions are at 9:30 AM, Classroom A, are
free and are limited to students under 21 years of age.

For reasons that are obvious to anyone who has priced
lettuce in the supermarket, Gilbert White’s comments of
1778 still hold true: “As to the produce of the garden, every
. . . person of observation may perceive, within his own
memory, both in town and country, how vastly the con¬
sumption of vegetables is increasing . . . every decent
labourer also has his garden, which is half his support, as
well as his delight . . .” Dick Hannigan’s courses in Vegetable
Gardening will touch on all phases of growing a garden,
including seeding, care and cultivation, soil, insects, varieties
and watering. The day class is from March 8 to April 5, 10
to Noon and the evening one March 9 to April 6, 7 to 9
P.M. The cost is $10.00 for members and $15.00 for
non-members.

Two classes in Basic Bonsai will also be offered, one in
the evening from March 8 to March 29 and one in the
mornings from March 9 to March 30. The cost of $12.00 for
members and $17.00 for non-members includes the price of
soil and wire. However, the trees will cost extra — approxi¬
mately $10.00 per tree. Limit 15 students in each class.

A free class in Basic Taxonomy will help prepare
students for the field trips later. (The first of the season will
be on March 17 at 9 A.M.; meet at 909 York Street.) Learn
how to look at a plant. The arrangement of sepals, petals,
stamens and pistil all are indications of family, genus and
species. Once you learn to use your eyes, you will recognize
many of the wild cousins of our garden flowers. Dr. Zeiner
will teach this free class at 9:30 A.M., March 9, Classroom
C.

The natives will also be featured later in the month
when Dr. Feucht will teach Identification of Shrubs. This
will begin on March 17 at 10 A.M. and the cost is $10.00
for members and $15.00 for non-members, limit 20.

(And speaking of taxonomy, do read The New Yorker
article of January 12, 1976. This recounts in a most
interesting fashion the search for Betula uber.)

The Annual Rose Symposium is scheduled for Saturday,
March 13 at 9:30 A.M. in Horticulture Hall. This workshop
provides a wonderful opportunity to hear knowledgeable
speakers on a variety of rose growing topics. Ample time will
be allowed for questions.

If you have success with your roses this year, you might
like to make some old fashioned scented jewelry that was
popular in Victorian times.

The principal ingredient in rose ebony beads is fragrant
rose petals, which are ground in a food grinder. The pulp
and juice are thoroughly stirred in an iron skillet, which
turns the mixture black. It is left in the skillet for a day,
and turned occasionally to make certain it is entirely black.
Then the mixture is ground again, dried and ground again.
This latter process is repeated daily for nine days. On the
final day a little water is added, after 'Which the ebony
mixture is rolled into little round balls. A pin is inserted
through each one, and they are left to dry.

After a few days the pins are removed, and the small
balls become beads that can be strung. The beads are hard
and durable, and smell like roses from which they were

derived. They retain their fragrance for many years. (Recipe,
courtesy the All-American Rose Selection News.)

This day, devoted to roses, will be culminated by a free
film, “The World of Roses” at 1:30, Classroom C.

Another opportunity to learn more about roses will be
provided on March 27! Expert rosarians will take small
groups into the garden and there proper pruning techniques
will be demonstrated. This is scheduled from 10 a.m. until 2
p.m. (come and go as you wish) but please meet in
Classroom A.

Beginning Flower Arrangement, March 17 — April 7, 7
to 9 P.M., Classroom B, will teach participants how to use
color and design most effectively in bouquets for the home.
The cost which includes all flower material is $20.00 for
members and $25.00 for non-members.

Finally on March 20, Barbara Hyde will discuss Home
Landscaping. This is to be an illustrated lecture and parti¬
cipants will receive a C.S.U. Bulletin on the subject. Meet at
9:30 A.M., Classroom C. The cost, to be paid at the door, is
$1.00 for the Bulletin.

You are cordially invited to attend the Annual
Membership Dinner on Thursday, March 11th at
Horticulture Hall. The speaker will be Mr. Andrew
Pierce, Superintendent of Conservatory and Green¬
houses at the Denver Botanic Gardens. His topic will
be “The Flowering Island”. The social hour is planned
for 6 to 7 P.M., followed by dinner at 7 P.M.

Wild Flower Lecture

Mr. Lou Hagener, Chairman of the Science Department of
Northern Montana College, will give an illustrated lecture on
March 23 on Wild Flowers of Northern Montana and
Southern Alberta.

Mr. Hagener, who has written several booklets on vegeta¬
tion of northcentral Montana, is currently working with the
Canadian government on establishing a prairie wilderness area
in Alberta.

The lecture, free and open to the public, will be at 8 p.m.
in Horticulture Hall, 1005 York Street. All welcome.

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4th Annual Used Book Sale

It’s that time of year again when the Library Volunteers
will start sorting and pricing used books for this year’s sale
on May 7 and 8. Some members and their friends have
promised books which haven’t come in yet. Help us to avoid
that last minute crush and bring in your contributions soon.

Isn’t anyone parting with Gourmet and Horticulture
magazines this year? We’re already inundated with Sunset,
House & Gardens, Flower Grower, etc., but hardly any
Gourmet or Horticulture . We need all kinds of paperbacks,
and for some reason we’re short on mysteries. You remem¬
ber we collect books for this sale all year long.

You helped us to buy $2500 of books for the Library
this past year. We’ll need to take in almost $2700 this year
just to keep even with inflation, and we don’t want to just
keep even. Will you help us to aim for $3000?

Some of the books that you helped purchase are among
these recent additions to the Library collection.

Darnell, A. W., Unfamiliar Flowers For Your Garden.
Blashfield, Jean F., Apartment Greenery.

McDonald, Elvin, Little Plants for Small Spaces

Smith, Alexander H., A Field Guide to Western Mushrooms.

Coats, Alice M., The Treasury of Flowers.

Van Rooten, Luis, The Floriculturist’s Vade-Mecum of
Exotic and Recondite Plants . . .

Jorgensen, Jay, Landscape Design for the Disabled.

When visiting the outside gardens, look for Iris histrioides, one of
the most pleasant of all minor “bulbs”. Since these beauties can
stand battering by the elements, even when snow is on the ground,
you’ll spot a flash of vivid bjue with just a dash of gold. Iris
reticulata comes a little later, grows a little taller and is dressed in
purple.

And look for tulips both in the Lobby Court and outside. We
received boxes and boxes of tulips from the Netherlands Flower-bulb
Institute, Inc. all blazened with “Happy Birthday, U.S.A.” Of the
10,000 bulbs received, watch for the early red and white Emperors.
Later ‘Hollands Glory’ a" red orange, ‘West Point’ a yellow and
‘Smiling Queen’ a pink will be worth admiring.

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1976 CHILDREN’S GARDEN PROGRAM

Registration for beginning gardeners will be March 17 to
March 31. Children currently in the 4th, 5th or 6th grades
are eligible. Registration forms will be mailed on request.
For further information, call Bev Nilsen, 297-2547, Ext. 6.
If you wish to learn more about this program, be sure to
read the March Ranger Rick magazine. There is a very
interesting article about our Children’s Garden and the
illustrations by Loraine Yeatts are also well worth studying.

*******

The Botany Club meeting on March 19 will feature a
talk on Cacti by Virginia Simmons. All welcome at 7:30
P.M., Classroom C.

“Meet the Grasses” by Helen Zeiner will be the featured
topic at the March 21st meeting of Around the Seasons
Club. Visitors are welcome to attend the meeting at 1 1
A.M., 909 York Street.

Green Thumb Newsletter is published monthly by Denver Botanic Gardens,
Inc., 909 York Street, Denver, Colorado 80206. The Newsletter is included as a
benefit of membership in the Denver Botanic Gardens, regular membership dues
being $10.00 a year. Items for publication are welcome. The deadline for copy
to the editor is 2:00 p.m. on the 10th of each month preceding publication.
Editor — Margaret Sikes, 297-2547, Ext. 23.

Green Thumb Newsletter

DENVER BOTANIC GARDENS, INC.

Copyright 1976

NUMBER 76-5 MAY 1976 TELEPHONE 297-2547

GARDENING TIPS FOR MAY

This is the month when gardening gets into full swing.
All the plans that you might have made during the winter
and early spring months can now be implemented.

By the middle of the month it should be safe to put out
all the bedding plants except for tomatoes and peppers.
These are probably best protected from possible cold
weather until the end of the month. Tomatoes and peppers
don’t develop well until nighttime temperatures average
above 50 degrees F. Setting them out earlier often causes
them to delay in fruit set.

Hopefully you waited until now to apply fertilizers on
the lawn. If your lawn needs it, this would be a good time
to put on a standard 20-10-5 analysis fertilizer plus iron.
This is a good combination. If you apply this at the rate of
approximately five pounds of fertilizer for every one
thousand square feet, you will be putting on the actual
recommended one pound of nitrogen. There is no need to go
higher because this often forces soft growth that may be
subject to fungus diseases.

If you have had trouble with crab grass in your lawn,
pre-emergent control materials can often be put down early
in the month. Most any of them on the market are suitable.
Probably one of the most common is Dacthal. This chemical,
as with all pre-emergent herbicides, is designed to stop the
growth of crab grass seed as it sprouts. It has no effect,
however, if applied too late because it will not control
seedlings after the roots have penetrated the soil. Be sure
you don’t mistake crab grass with quack grass. Quack grass is
a perennial and if you have that, there are no satisfactory
controls other than trying to dig it out. This is often a very
frustrating task because you are more apt to propagate it
than you are to control it.

You may also have perennial bunch-type grasses in your
lawn. If they are bunch-types that do not develop ground
runners of rhizomes, the easiest way to control these is to
dig them out and patch in with pieces of sod. Use the sod
from along the edges of your yard such as in areas where it
is tending to creep into flower beds and shrub borders. When
lifting a piece of sod, don’t attempt to take a deep soil layer
with it. Sod is better cut thinly, no more than about one
inch. This may seem severe treatment but it does promote
better re-rooting and rhizome development than if you take
a thick portion of sod.

This is also a good time to control dandelions and other
broadleafed weeds in the turf. Use a liquid weed control
material containing 2, 4-D and Sylvex. Make certain that you
dilute it according to directions and apply it on a wind-free
day so that you avoid drift into desirable plants. If you have
just a few weeds in your lawn, I have found that it is safer
and much more practical to use spot treatment rather than
spraying the entire law. There are inexpensive applicators
that are simply plastic tubes with a valve at the bottom that
releases the chemical when the device is pushed. The weed
control chemical is available for these applicators in a solid,
tablet form already premeasured for you.

Be on the watch for certain insect pests that seem to be
quite devastating this time of year. Leaf rollers, particularly
in crab apples, will appear at a time when the young leaves
are unfolding and at about the same time the trees are in
bloom. Don’t rush out and spray, however, if you see leaf
rollers at that time. To avoid killing bees you should wait

until nearly all of the petals drop. As soon as petal fall has
occurred, apply malathion to any leaves showing signs of the
leaf rollers. The earlier you catch them, the more effective
the control.

The same would be true of tent caterpillars which can
be very devastating in a short period of time. Because of the
mild winter I anticipate high populations of these two
insects.

If you have spruce, fir or Douglas fir and, particularly, if
you live in east Denver, Littleton or Englewood, be on the
lookout for the tussock moth. Hatch normally begins some¬
time in mid-May and by the middle of June, extensive
feeding causes the total loss of the tops of the trees if
allowed to go undetected.

Because the tussock moth is so difficult to see when the
larvae have hatched from the eggs and because they are
usually in the tops of the trees, a good way to detect them
is to stake down a sheet of paper or plastic near the trunk
of the tree and watch daily for little bits of needles and
yellow, sand-like droppings. If this occurs, spraying is
warranted. If the trees are small enough to be able to reach
their tops with your own spray equipments, three sprays
about one week apart with malathion or diazinon will give
good control. It is important, however, that the entire tree,
including the tops, be saturated with the spray. If your trees
are too big to spray adequately with your own equipment,
secure the services of a professional arborist. If you spray
your own trees, be sure to follow the directions on the label.

We have received over the past few years, a number of
inquiries on the control on pinyon borers. These are evi¬
denced by masses of pitch, usually found in the crotches of
the trees beneath which are cream-colored larvae which cause
the damage. Unfortunately, there are no control measures
known and about the only way to try to get rid of them is
to dig them out of the pitch with a pocket knife.

You may wish to try applying Lindane as a preventative
and this should be put on now. It should be applied as a
spray directly to the bark of the main trunk, paying
particular attention to deposits of the Lindane in the branch
crotches. A degree of control can be attained through good
cultural practices. The borers seem to prefer pinyon that are
under stress and in most home gardens, the stress is due to
poor aeration of the soil, accentuated by poor watering
practices. Established pinyon should be allowed to stay on
the dry side and can thrive perfectly well on natural
moisture. Avoid watering your pinyon every time you water
the lawn. If you have a sprinkler system, it might be well to
adjust the heads in such a way as to direct the water away
from the trees. It is also a good idea to keep the soil
beneath the trees cultivated by shallow hoeing. You can also
aerate more deeply using a soil needle device such as the
Ross Root Feeder.

Make it a practice to take a weekly tour of your yard
and notice the changes taking place. This not only helps you
enjoy the dynamic phenomena that occurs in a garden from
week to week, but will help you to determine any possible
problems. Often it is not necessary to apply control
measures when you begin to see that the problem is really
not becoming serious or it may turn out to be no problem
at all. In this way, gardening becomes a joy and a learning
experience, rather than a chore.

Dr. J. R. Feucht

It’s that time again!

Everywhere around the Denver Botanic Gardens things
are busier than usual getting ready for the Plant Sale. Join us
on May 7 and 8 from 9:30 a.m. to 5:30 p.m. in and around
the Boettcher Memorial Center and don’t forget to admire
the Lobby Court with its pink and white mums and roses
while you’re here.

A special feature will be the red, white and blue garden
booth. One border to consider would use red salvia at the
back and blue ageratum and white alyssum in the fore¬
ground. If you want to get fancier, what about a bicen¬
tennial ’76 flag, a liberty bell, or a bicentennial star?
Information as to layout, suggested plants and planting is
available in the Library.

While there, be sure to go downstairs to see some 5000
(Jsed Books on all subjects for sale in the basement of the
Library, as well as the tremendous number of magazines
including Flower & Garden, Horticulture, Audubon, Smith¬
sonian, National Geographic, and many western magazines.
Most books are priced under a dollar and the magazines are
mainly priced at twenty-five cents or less.

In the House Plant section, we will have more varieties
of hibiscus, bougainvillea and bromeliads than ever before —
plus a larger selection and more unusual carnivorous plants.
The orchid selection will have Phalaenopsis, Paphiopedilums,
and many others. Of unusual interest will be the “Mickey
Mouse Plant,” or Ochna. It has an orange flower which is
followed by green, then black berries. Also available will be
flowering plants for Mother’s Day, cacti, palms and hanging
baskets, plus many tropical plants found in the Denver
Botanic Gardens Conservatory.

Buyers at the Vegetable Booth will find many old and
new varieties of tomatoes, suitable for growing in a garden,
or in a patio container. Among the newer varieties will be
‘Big Girl’, ‘Gardener’s Delight’, and ‘Tumbling Tom’. We will
have Pascal celery, broccoli, cabbage, peppers, cucumbers,
cantaloupe, and watermelon. New and old varieties will be
offered along with tips for success in growing them.

Help in planting a kitchen garden, including chives,
marjoram, basil, thyme, bumet, rosemary, oregano, tarragon
and savory will be available at the Herb Booth. These old
stand-bys, a must for every good cook, may also be used in
interplanting with your flower garden. Thymes, low growing
evergreens, are excellent as borders around upright ever¬
greens. Corsican mint creeps into a lovely mat around your
favorite plant. Rosemary and oriental garlic provide an
attractive contrast to your perennial border. And don’t
forget the scented geraniums for their fragrant leaves.

The Berry Basket Booth has increased the quantity of
plants this year so that there will be plenty for all. Among
the assortment will be raspberries, gooseberries, grapes,
currants, and strawberries.

Using flowering Annuals, it is only proper to go
“patriotic” in 1976 with bright reds, glistening whites, and
vivid blues. An all-petunia display can be arranged in
different and creative designs or for the shady spot, we have
red and white impatiens with blue pansies, or lobelia. If
patio gardening is your forte, consider red and white
geraniums or begonias, and maybe add blue petunias (or
Nierembergia ) to get the blue effect. For the rock gardens,
alyssum, verbena and ageratum may be considered. These are
only a few selections of the wide variety of plants that will
be offered for the “Spirit of ’76” gardener at the Plant Sale.

Again, among the native wild flowers and ground covers
featured at the Rock Garden Booth will be a red flowered
cinquefoil, Potentilla thuberi. This native of New Mexico and
Arizona has been grown especially for this sale. It is hardy at
8,500 elevation and blooms from July into September and
October.

Other popular natives include blue-eyed grass, as well as
pink plumes and pussytoes. A red penstemon, Penstemon
pinifolius, resembles tiny junipers growing in a mat with
vermilion red spikes six to eight inches tall, and is an
excellent ground cover. Among cultivated plants will be
sunroses in various colors, coral bells, unusual sedums,
named varieties of hen and chicks, plus various pinks,
penstemons and veronicas.

Two columbines, the alpine Aquilegia saximontana, with
dainty white cup and blue saucer on three-inch plants and
the blunt-spurred red columbine, A. elegantula on plants less
than a foot high, will be prized by dedicated rock gardeners.
Of course, Colorado columbine, A. caerulea, will be available
also. The Colorado columbine was designated our state
flower in April 1890. It has blue and white blossoms, 2 to 4
inches broad with long slender spurs and grows tall in shady
locations.

The Patio Plant section has offerings from small to large.
Among the small are handing baskets of wandering jew in

DENVER BOTANIC GARDENS
CALENDAR OF EVENTS

MAY, 1976

MAY

3)

10:00 a.m.

Botanic Gardens House

Historic Denver House Tour

OPEN TO PUBLIC: 10:00 a.m. - 6:00 p.m.

4)*

10:00 a.m.

Herbarium

Herbarium Committee Meeting

4)*

1 :00 p.m.

Botanic Gardens House - Dining Room

Editorial Committee Meeting

4)

7:00 p.m.

Botanic Gardens House — Main Room

Denver Audubon Society (WildlifeWorkshop)

4)

7:30 p.m.

Education Building — Lecture Room “B”

Denver Bonsai Club

5)*

9:45 a.m.

Botanic Gardens House — Main & Dining Rooms

Ikebana International

5)*

3:30 p.m.

Botanic Gardens House — Main Room

Children’s Garden Meeting (Advanced)

5)*

7:30 p.m.

Botanic Gardens House — Main Room

Colorado Mycological Society (Workshop)

6)*

10:00 a.m.

Education Building — Prep Room

Ikebana International

6)*

7:45 p.m.

Botanic Gardens House —

Main - Dining & Kitchen

Denver Orchid Society Meeting

7)

9:30 a.m.

Education Building, Horticulture Hall
& Surrounding Area

Annual Plant Sale

OPEN TO PUBLIC: 9:30 ajn. - 5:30 pan.

7)

11:00 a.m.

Botanic Gardens House —

Main - Dining & Kitchen

Civic Garden Club

8)

9:30 a.m.

Education Building, Horticulture Hall
& Surrounding Areas

Annual Plant Sale

OPEN TO PUBLIC: 9:30 a.m. - 5:30 p.m.

10)*

1:00 p.m.

Education Building — Lecture Room “B”

Garden Club of Denver

10)

7:30 p.m.

Education Building — Horticulture Hall

Colorado Mycological Society Meeting

10)

7:30 p.m.

Botanic Gardens House - Main Room

Denver Sierra Club

11)*

9:30 a.m.

Education Building — Lecture Room “B”

Civic Garden Club — Division “C”

11)*

1:00 p.m.

Education Building — Lecture Room “B”

New Roots Garden Club — Meeting and Tour

11)*

4:00 p.m.

Botanic Gardens House — Dining Room

Executive Committee Meeting

11)*

7:00 p.m.

Education Building — Herbarium

American Society of Landscape Architects

11)*

7:30 p.m.

Education Building — Lecture Room “C”

E.C.C. Nature Study Unit

12)*

7:30 p.m.

Education Building — Lecture Room “C”

Colorado Mycological Society (Workshop)

12)*

7:30 p.m.

Botanic Gardens House — Dining Room

Landscape Industry Council

13)*

10:00 a.m.

Education Building — Prep Room

Ikebana International

13)

7:30 p.m.

Botanic Gardens House — Main Room

Denver Rose Society

14)

All Day

Education Building — Horticulture Hall

Parks & Recreation Program

14)*

9:00 a.m. —
3:00 p.m.

Education Building — Service Area

Plant Give-A-Way to Members

14)

7:30 p.m.

Botanic Gardens House —

Main - Dining & Kitchen

Denver Dahlia Society

15)*

9:00 a.m. —
1:00 p.m.

Education Building - Service Area

Plant Give-A-Way to Members

15)*

9:30 a.m.

Educational Building — Lecture Room “B”

Hi-Country Judges Workshop

15)*

1:00-
10:00 p.m.

Education Building, Horticulture Hall &

“A” - “B” & “C”

Nature Conservancy Annual Meeting &
Catered Dinner

♦ ♦♦♦♦♦♦♦

♦ ♦

18)

7:30 p.m.

Botanic Gardens House —

Main - Dining & Kitchen

Rocky Mountain African Violet Council

18)

7:30 p.m.

Education Building — Horticulture Hall

Sierra Club

18)

7:30 p.m.

Education Building — Lecture Room “B”

Denver Bonsai Club

MAY CALENDAR OF EVENTS (Continued)

19)

9:00 a.m.

Botanic Gardens House — Parking Lot

PLANT LIFE FIELD TRIP - Dr. E. H. Brunquist

19)

7:00 p.m.

Education Building — Horticulture Hall

Sierra Club (Back packing)

19)*

7:30 p.m.

Education Building — Lecture Room “C”

Colorado Mycological Society (Workshop)

20)

7:30 p.m.

Education Building — Lecture Room “A”

Colorado Open Space Council

20)*

7:30 p.m.

Education Building — Lecture Room “B”

Colorado Bonsai Club

20)

7:30 p.m.

Education Building — Lecture Room “C”

Organic Garden Club

21)*

9:00 a.m.

Education Building — Lecture Room “B”

Dyeii g with Plants — Mrs. Carol Hoffman

21)

7:30 p.m.

Education Building — Herbarium

Dem er Botany Club

22)

10:00 a.m.

Education Building — Horticulture Hall

Ikebana International Show

OPEN TO PUBLIC: 10:00 a.m. - 5:00 p.m.

22)*

1:00 p.m.

Education Building — Lecture Room “B”

Dyeing with Plants — Mrs. Carol Hoffman

23)

10:00 a.m.

Education Building — Horticulture Hall

Ikebana International Show

OPEN TO PUBLIC: 10:00 a.m. - 5:00 p.m.

♦ ♦♦♦♦♦♦

♦ ♦ ♦

24)*

9:30 a.m.

Botanic Gardens House — Main Room

New African Violet Club

24)

7:00 p.m.

Education Building — Horticulture Hall

Sierra Club (Back packing)

24)*

8:00 p.m.

Education Building — Lecture Room “A”

Nature Conservancy

25)*

9:00 a.m.

Education Building - Flower Prep Room

Ikebana International

25)*

4:00 p.m.

Botanic Gardens House — Conference Room

Board of Trustees Meeting

25)

7:30 p.m.

Education Building — Lecture Room “C”

Gladiolus Society Meeting

26)

10:00 a.m.

Botanic Gardens House — Main Room

Plant Sale Meeting - Mrs. H. Franson

27)*

10:00 a.m.

Botanic Gardens House — Main Room

Around the Seasons Meeting

27)

7:00 p.m.

Education Building — Horticulture Hall

Sierra Club (Back packing)

27)*

7:30 p.m.

Botanic Gardens House —

Main - Dining & Kitchen

Denver Men’s Garden Club

28)*

10:00 a.m.

Education Building — Horticulture Hall

Ikebana International

29)

1:00 p.m.

Education Building — Horticulture Hall

IRIS SOCIETY SHOW (Weather permitting)

OPEN TO PUBLIC: 1 :00 - 4:45 p.m.

30)

9:00 a.m.

Education Building — Horticulture Hall

IRIS SOCIETY SHOW (Weather permitting)

OPEN TO PUBLIC: 10:00 a.m. - 4:45 pan.

♦ ♦♦♦♦♦♦

♦ ♦ ♦

JUNE

1)*

10:00 a.m. .

Education Building — Herbarium

Herbarium Committee Meeting

1)*

1:00 p.m.

Botanic Gardens House — Dining Room

Editorial Committee Meeting

1)

7:00 p.m.

Education Building — Lecture Room “C”

Denver Audubon Society

1)

7:30 p.m.

Education Building — Lecture Room “B”

Denver Bonsai Club

2)

7:00 p.m.

Education Building — Horticulture Hall

Sierra Club (Back packing)

3)

7:30 p.m.

Education Building — Lecture Room “C”

Colorado Open Space Council

3)*

7:45 p.m.

Education Building — Horticulture Hall

Denver Orchid Society

*MEMBERS OR ENROLLEES ONLY

THE JOLLY GREEN

MAY 1976 Vol. 6, No. 3 (For Junior Members)

DENVER BOTANIC GARDENS

DENER

NEWSLETTER

©§7§7©(#

Did you know that one of the oldest fibers in
the world is cotton fiber? Cotton cloth, which was
estimated to be seven thousand years old, has been
found in caves in Mexico. As long as five thousand
years ago, cotton was grown, spun and woven in
Pakistan and Egypt. For centuries Arab traders
bought cotton from India and the Orient.

Cotton has always been an important com¬
modity in the economy of the United States. In the
early 1600’s southern regions produced cotton and
shipped most of it to the mills in England which
spun the raw cotton into cloth. In 1790, America’s
first spinning mill was founded in Pawtucket, Rhode
Island.

blossom

boll

In 1791, Eh Whitney, of Massachusetts, invented
the Cotton Gin. This hand cranked machine
separated the fiber from the seed fifty times faster
than a slave could do it by hand. With factories
growing and the demand spiraling it was now
possible to increase the supply. The United States
grew to be a world leader in cotton production and
today we produce about 40% of the world’s supply.

Why is cotton so valuable? The cotton fiber is 1
- 1-1/2” long which is longer than most fibers. It
also has a unique natural twist which holds the
thread together for weaving. Hundreds of products
contain cotton and it is an integral part of our life.
Millions of jobs here in America depend on cotton
and billions of dollars are invested in it.

Over 500,000 farms in the United States, from
Carolina to southern California, produce cotton.
Most farms are mechanized and scientifically
managed with an array of equipment over $50,000.

The flower buds on the plants are called
squares. These appear two months after planting.
They blossom quickly in the hot sun. At first these
flowers which resemble hollyhocks, are white in
color. They quickly change to pink and then to
dark red. In three days they are gone. When the
petals fall, the small green pods mature into cotton
bolls. The boll grows to the size of a walnut and
within 45-60 days bursts open to show the fluffy
white cotton fibers. This is what harvesters pick and
process.

Many insects thrive on the cotton plant. Perhaps
the best known is the boll weevil. It is certainly the
worst pest to the cotton plant. The female weevil,
which, is about the size of a housefly, lays her eggs
in the flower bud. When the eggs hatch, the grubs
feed on the boll and maturing cotton fibers. To
date no chemical has been developed which can
eradicate this insect. It causes great damage yearly
and can only be partially controlled.

After the cotton is harvested and cleaned, the
fiber called lint is pressed into tight 500 lb. bales
and sold. Many products contain cotton. You might
go through the alphabet and list those you know.
Start with A for abrasives and end with Z for zipper
tapes.

Perhaps you are unaware of the fact that the
cotton seed is also one of our country’s most
important crops. The seeds are processed at oil
mills. The outer fuzz of the seed is removed and
used to make rayon, plastics and varnish. The meaty
inside is used for oils for margarine, cooking and
salad oils. The dry seed remains are used to make
fertilizers and to feed livestock.

Answers to picture quiz in March issue:

(1) daffodil (2) tulip (3) hyacinth
(4) grape hyacinth (5) crocus

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PLANT SALE

Denver Botanic Gardens
1005 York Street

May 7 & 8, 1976
9:30 - 5:30 p.m.

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Do you know these flowering plants?
One is the Colorado State Flower

A special feature at the Plant Sale this year
will be the Red, White and Blue garden
rMS Booth. Why not try a bicentennial design this

/Ha year in one of your flower beds at home.

Perhaps you would enjoy a flower bed de¬
signed as an American flag, or in the shape of a bell or a
star. Information as to different garden designs and
plants to use to make them is available in our library.

How about getting a plant to give to your mother
on Mother’s Day which is the day after the Plant Sale?
There are many plants to choose from in the house
plant section, even carnivorous plants. The Herb Booth
will have basil, chives, thyme, tarragon, oregano, mint
and scented geraniums. In the Berry Booth you will
find raspberries, currants, grapes and strawberries.
There will also be annuals, perennials, trees, shrubs
and rock garden plants. If you prefer a non-plant item
stop by the Gift Shop.

FRUIT LEATHER
A PIONEER CANDY

Fruit leather is made from very ripe fruit — use
apples, peaches or pears. First make a fruit “butter”
by peeling, coring and slicing the fruit. Simmer on
top of the stove in one inch of water until soft.
Push fruit and liquid through a food mill. Pour
mashed fruit into a large baking pan and add sugar
to taste. Also add spices, cinnamon or ginger if
desired. Stir well. Bake in a 300° oven for several
hours, stirring every 20 minutes.

When this butter is very thick spread half-inch
deep on a lightly greased pottery pie plate. Set in a
sunny spot, covered with netting, to dry. This is
finished when it is dark brown and leathery. Cut
into strips. Good for camping.

{horn American Cookery , by James Beard)

4-1/2” pots to the other end of the scale: one-half bushel
size mother geraniums. Of course, we’ll have hundreds of
other geraniums, also including ivy geraniums, and the
once-blooming Martha Washington. A newly developed plant,
the double impatiens, which looks just like a miniature rose,
will be featured in hanging baskets. After searching many
greenhouses, we finally found the hanging ice plant, a rarity,
and are lucky to have it! For a great buy, we found 4” tall
and very full jade plants which will double in size on your
patio this summer. Be sure to keep them out of direct sun
or the sun spots will be more than something you read
about in scientific journals.

Patio trees in many variations are a new find this year.
We also will have the patio and ‘Tiny Tim’ tomatoes,
fuschias, begonias, and for those who want carefree plants,
the easy to grow Asparagus sprengeri, spike Dracaena and
vinca in pots and hanging baskets.

You will find a wide variety of hardy Perennials
arranged in alphabetical order from A to Z. Included will be
the old-time favorites — bleeding heart, delphinium, iris,
peony and phlox, as well as the not so familiar Astilbe,
Baptisia, Catananche, Dictamnus, Platycodon and many
others. Many new and improved varieties will be available.

Trees and Shrubs will feature rare and common woody
plants. Would you like to try Franklinia alatamaha? In the late
1700’s William Bartram sent specimens of this tree to his
father’s garden in Philadelphia, where it was named in honor
of Benjamin Franklin. It has never again been found in the
wild and all known specimens are from those he collected.
Other plants are Hedera helix ‘Pixie’, Lagerstroemia indica
‘Petite Pinkie’, and ‘Petite Snow’, Lantana camara ‘Christine’
and ‘Sunset’, all trained as 2-foot high patio trees; Juniperis
chinensis ‘Mint Julep’ trained as a topiary turkey, and J.
virginiana ‘Sky Rocket’ as a narrow pillar. Others to watch
for include Viburnum x carlcephalum and Platanus acerifolia
‘Bloodgood’ which is more resistant to anthracnose. People
who heard Mr. Eickhorst talk may want to try Rhodo¬
dendron nudiflorum ‘P.J.M.’ and Mollis hybrid azaleas.

Pomegranate, cryptomeria, cypress, and cherry will be
among the new trees offered this year at the Bonsai Booth.
This will complement the old favorites of red maple, black
pine, and bamboo. Pots and instructions will also be avail¬
able to create your own, or there will be an assortment of
already-potted bonsai or saikei. There will also be an
instructor of Bonsai for demonstrations in the afternoon at
this booth.

Last year 130 memberships were sold and again this
year we know the Membership Booth will be busy telling
about the benefits that the Gardens have to offer.

Please remember that volunteers are needed in all areas.
Call now to learn how you may help. Did you see the April
Better Homes and Gardens where an emphasis in the Denver
Botanic Gardens article was on all that the volunteers do
here? You deserve all the credit we can give!

Bonus Plant Give-away, May 14-15

Again this year members will receive a bonus plant
which the Gardens wishes to share with its members. To
obtain the plant, members should come between 9 a.m. and
3 p.m. on Friday, May 14 or 9 a.m.' until 1 p.m. on
Saturday, May 15. The membership card should be presented
at the garage building on the north side of the service area,
west of the greenhouse. (It is the same area as last year but
for those of you who are new members, or were not able to
come before, enter the Gardens at the Gaylord St. entrance,
off 11th Ave. Turn right to reach the service area.)

Most plants to be given away are woody plants, mainly
shrubs and all are in containers. Since some members live in
apartments, there will be a few house plants available also.
Plants will be labeled and have brief culture instructions
attached. Some of the following will be available on a
first-come-first served basis: Buddleia ‘Opera,’ Caryopteris
‘Azure,’ Elaeagnus angustifolia var. orientalis, Pachystachys
hi tea, Ruellia spicata and Syringa julianae.

Please remember the dates and hours and bring your
membership card (only one plant for each card, please).

COLORADO’S CENTENNIAL-BICENTENNIAL
1976 IRIS SHOW

Horticulture Hall - Denver Botanic Gardens
1005 York Street

Saturday May 29 1 PM to 5PM

Sunday May 30 10 AM to 5 PM

The public is invited without admission charge to view the show iris
and/or enter horticultural stalks and/or arrangements.

Those viewing the show during the above hours will see displayed the
region’s finest iris. The show is timed for peak bloom of the
outstanding Tall Bearded variety. The latest new iris introductions
will be separately featured by commercial growers. An artistic
arrangement division will have a tour-of-Colorado section; other
sections will show Aril iris, Beardless iris, seedlings propagated by the
region’s hybridizers, and youth horticultural stalks and/or
arrangements.

Those wishing to enter stalks and/or arrangements can obtain
schedules by calling either of the show co- chairpersons:

Marguerite Vigil 935-2695
Ray D. Lyons 985-7030

GARDENING FOR THE YOUNG

The Denver Botanic Gardens is offering two programs
this spring-summer for young gardeners: the Children’s
Garden, which has been a big success in the past, and a new
program for advanced children, the Advanced Youth Garden.

The Children’s Garden across the street from the
Education Building, is for children in the fourth, fifth and
sixth grades. They learn how to design, plant and take care
of their own vegetable garden by actually doing the work on
a plot assigned to them!

The Advanced Youth Garden is for three year graduates
of the Children’s Garden. They study more advanced topics,
such as: French intensive gardening, growth of hybrids and
varieties, grafting, soil preparation, alteration and analysis,
and more! They too have their own plot assigned to them to
work on. The formal name of this garden is the Ruth Porter
Waring Youth Garden; it is situated to the north of the
Education Building.

Both of the gardens have very competent instructors.
Lee Schwade who is in charge of the Children’s Garden is a
Botanist-Horticulturist at the Denver Botanic Gardens; he
was a high school science teacher previously. James Jackson
in charge of the Youth Garden has his PhD in Botany and is
presently teaching at the University of Northern Colorado.

Both programs are now open for enrollment. Hope to

see you young gardeners this summer! „

Sue Skubal*

*Sue Skubal is a Student Intern from East High School; she is
spending the semester at the Botanic Gardens to further her interest
in horticulture.

Mr. John C. Mitchell, President of the Board of Trustees, has
announced the election of the following members to the Board: Mr.
Junius F. Baxter, Mr. William R. Thurston.

s|c % % ♦ * *

Memorial gifts have been received in honor of David Krohn and
John Stein.

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MAY CLASSES

Remember the Tree Walk in Boulder on May 15. This
walk will start by making the circuit of Central Park, which
contains a number of quite unique deciduous and evergreen
trees. We will proceed down Arapahoe Ave., with several side
detours en route, ending at Folsom St. and returning to the
Public Library parking lot either by local bus or on foot.
Arapahoe is one of the oldest former residential streets, and
has a number of relatively rare trees, especially a very large
tulip tree, a large magnolia, an American chestnut, a sweet
gum and enormous sycamores. About 40 to 50 tree species
will be seen on this walk.

Meet at 9 a.m. at Boulder Public Library, Canyon Blvd.
west of Broadway. Free. Limit 20, no sign-ups before May 3,
please.

Dr. Brunquist will lead his regularly scheduled Field Trip
on May 19 at 9 a.m. at 909 York St. People who have been
inquiring about the purple flower carpeting the vacant lots
around Denver should come and learn about this Cruciferae
and other members of the Mustard family. Chorispora tenella
is a weed which is such a recent introduction that it was not
listed in the 1945 edition of Clements and Clements’ Rocky
Mountain Flora. Since then it has certainly made itself at
home!

Dyeing with Plants will be taught on Friday, May 21 at
9 a.m., Classroom B. Mrs. Hoffman will then meet the group
in the field in the morning of May 22, and that afternoon
return to the classroom. The fee, which includes materials, is
$4.00 for members and $5.00 for non-members. Limit 20.

If you are unable to attend but are interested in the
subject, look at Rocky Mountain Dye Plants, a new book by
Anne Bliss. It features such topics as Foraging for Dye
Plants; Predicting Dye Colors and Variations; Fiber, Yarn
and Fabric; Basic Amounts of Mordants; Preparing the
Dyebath; and Testing for Light Fastness.

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Finally, the Pawnee Grasslands Trip is scheduled for
May 29. Meet at 909 York St. at 7 a.m. or at Crow Valley
Park, along Highway 14 near Briggsdale at 9 a.m. Free, bring
lunch. Limit 20.

Those who wish to study this fascinating area in more
detail will be pleased to know that the Denver Audubon
Society will again have its Grassland Institute this year. The
Institute will convene at Briggsdale, Colorado, between June
13 and June 20, 1976. The Institute is an attempt to
describe the grassland ecosystem in multi-disciplinary terms.
Attention is given to effective utilization of the valuable
grassland resources. Participants reside at the campground
which is part of Pawnee National Grasslands.

Further information and registration materials may be
secured by contacting Dr. Jim Wright, 1227 S. Quince Way,
Denver 80231.

IKEBANA INTERNATIONAL

Ikebana International, Denver Chapter #66, is having its 9th
Japanese Flower Show, “Festival of Flowers,” on May 22 and 23,
1976 from 10 a.m. to 5 p.m. in the Horticulture Hall at the Denver
Botanic Gardens, 1005 York St., Denver, Colorado.

There will be several schools of Ikebana included in the show:
Chiko, Enshu, Ichiyo, Ikenobo, Koryu, Ohara, Sekka, Sogetsu, and
Tosen.

Demonstrations of flower arrangements by teachers and members
of the various schools will be given during each day of the show from
a Pergola in Horticulture Hall.

Several members from the Colorado Springs Chapter of Ikebana
International will be guest exhibitors.

Tickets may be obtained at the door or from Ikebana members
for $1.00 donation.

Thanks to so many of you who have contributed books and
magazines for the Used Book Sale which will be held on May 7
and 8. We have room for more things if you have more to give.
And do come to see what we’re selling!

Green Thumb Newsletter is published monthly by Denver Botanic Gardens,
Inc., 909 York Street, Denver, Colorado 80206. The Newsletter is included as a
benefit of membership in the Denver Botanic Gardens, regular membership dues
being $10.00 a year. Items for publication are welcome. The deadline for copy
to the editor is 2:00 p.m. on the 10th of each month preceding publication.
Editor - Margaret Sikes, 297-2547, Ext. 23.

Green Thumb Newsletter

DENVER BOTANIC GARDENS, INC.

Copyright 1976

No. 76-6 JUNE 1976 TELEPHONE 297-2547

GARDENING TIPS FOR JUNE

This has been one of the most colorful springs in recent
memory. Residents of Colorado who have lived here very
long can appreciate the fact that we have had lilacs in full
bloom and they were not harmed by a hard frost. Even the
crabapples, peaches, and apricots have been favored with
nice weather and some of the early flowering fruit trees will
actually bear fruit.

June is probably the month when one would like to sit
back and relax after all the activity in May such as planting
the bedding plants etc., but there are some things that can
be done now. These would include removal of weeds,
keeping the soil surface cultivated to improve aeration and
promote healthy plants, and to cut back the spent blooms of
early flowering shrubs, tulips, iris, daffodils. In order to
maintain healthy plants, however, avoid removing too much
foliage because the foliage is responsible for building bigger
bulbs or rhizomes for next year’s show. If you want to
promote even larger bulbs, try spraying the foliage with a
soluble fertilizer made specifically for liquid application.
Ra-Pid-Gro and similar products will give good results.

Spring flowering shrubs such as lilacs can be pruned
lightly now but only to remove the spent blooms. Avoid
shearing the tops because this will tend to make them
branch heavily near the top causing the plant to shade itself
out, resulting in a “leggy” look. Very early flowering shrubs,
as well as flowering trees, are now in the process of forming
the flower buds for next year. By the latter part of June
most spring flowering trees and shrubs have already formed
their flower buds and any top pruning after that will
severely reduce the quantity of bloom next year.

Garden Pests

Slugs might possibly be posing a problem now and they
can be controlled through cultural practices and also with
some chemicals. You can discourage slugs simply by avoiding
too frequent, light applications of water. Keeping the soil
surface moist at all times will promote slug populations.
Water deeply and only when needed. This technique will
help the plants and also keep slugs away. Slugs do not like
to crawl on a dry surface. It is best to check the plants for
moisture needs and water only when the soil feels dry or
when the plants begin to show a slight wilt.

Frequent afternoon rain storms, however, do not give us
the chance to keep the soil dry. In that case, slugs can be
controlled with Metaldehyde but because this is very
poisonous, it is best used in a location where pets or birds
cannot get to it. One trick is to use a length of black plastic
pipe or similar tubing, place the Metaldehyde towards the
center of the tube and then place it in the garden in shaded
locations such as under shrubs. >

Another method is to bury coffee cans and other
containers in the ground so that the rim is level with the soil
surface. Pour a small amount of beer in each of the cans.
Slugs are attracted to the beer, will crawl into the can and
drown. What a way to go!

The early part of the month is a good time to look for
the crawler stage of oyster shell scale and also the pine
needle scale. Oyster shell scale will be found on dogwood,
cottonwood, aspen and other common trees and shrubs. The
scales themselves resemble tiny grayish shells. These have
been present all winter. Underneath the scales are the eggs
that would now be hatching. Diazinon and malathion will
give good control. Pine needle scale is white and is present
on the needles. It sometimes resembles tiny flecks of white¬
wash or paint. It is not only found on pines but also on
spruce. Malathion and diazinon are also appropriate for the
crawler stage of these. It is generally best for scale control to
apply three applications, spacing them about 7 to 10 days
apart. This will catch some of the overlap in the hatching of
the crawlers..

The early part of this month is also the time when
tussock moth does the most damage to spruce, fir and
Douglas-fir. These caterpillars work at the top of the tree
and quickly devour the soft growth, causing the trees to turn
brown. Sometimes it is hard to tell whether they are active
in the trees because they work at the top which is difficult
to see. To detect them, stake down a piece of white paper at
the base of the tree near the trunk and look daily for the
presence of bits of chewed needles and yellow droppings. If
you see these, control measures are warranted. On large
trees, use the services of a professional arborist but if the
trees are small enough that you can reach the top you can
use your own spray equipment. Diazinon will give excellent
control applied at least twice about 10 days apart. It is
important to thoroughly wet the entire tree with the spray.

Roses

June is the month for roses with most roses being at
their peak at the end of the month. When you cut flowers
for bouquets, or to remove withered blooms, be sure to
make the cut just above a leaf that has five leaflets. This will
then promote a new shoot for another flowering stock. It is
generally best to cut above a five-leafier leaf that is pointed
towards the outside of the plant. This will promote a more
desirable shape to the shrub. Following the peak blooming
period towards the end of June, apply a 5-10-5 fertilizer to
the roses, cultivating it 2 or 3 inches deep into the soil.
About one cup of fertilizer per plant distributed evenly over
the surface is adequate. After applying the fertilizer, water it
well. This will help to strengthen growth for continuous
summer flowering.

As new growth develops on roses, it is sometimes
afflicted by powdery mildew, particularly if the roses are in
a protected spot. Applications of benlate on a weekly vasis
will reduce and prevent this damaging fungus. Benlate is an
expensive material but is available in small quantities at some
of the garden centers. It only takes a small amount however,
and is extremely effective against mildew. If benlate is not
available, other alternatives include: Mildex, Karathane or
Captan. These materials are preventative only so must be
applied before mildew conditions occur. You can also reduce
the incidence of mildew by avoiding frequent watering of
the foliage.

After you have taken the precautions mentioned, you
can really sit back and relax!

Dr. J. R. Feucht

AUTOGRAPH PARTY

Several Colorado authors will be honored on June 17
from 2 to 4 p.m. in Horticulture Hall. Now is your chance
to come, have a cup of punch, and talk with people whose
work you have admired.

For those interested in wild flowers, Berta and Bill
Anderson, the new Editors of The Green Thumb magazine,
have written how many received their names. Botany,
history and biography are all included in Wild Flower Name
Tales.

George Kelly, who has written the bible for this area,
Rocky Mountain Horticulture, will have two new books hot
off the press! Plan to add these to your collection.

Another landscaping book, Grow Native: Landscaping
with Native and Apt Plants of the Rocky Mountains by Sam
Huddleston and Michael Hussey was reviewed in the Spring
1976 issue of The Green Thumb. Some particular helpful
features include three “watering schedules” which should be
of considerable assistance to everyone. Also very specific
suggestions are given on the planting of bareroot trees and
shrubs, container-grown and/or marketed, and those which
are balled and burlapped.

The Enchanted Mesa by Url Lanham deals with the
natural history of the beautiful forested table lands beneath
Boulder. Mr. Lanham concentrates on the conspicuous trees,
shrubs and wildflowers of the area plus the animal life that
may be seen.

Gene and Dee Milstein from Applewood Seed Company
will be available on June 17 to discuss Water, Light and
Love. This complete guide to growing healthy plants from
seeds, emphasizes wildflowers, tropical plants, culinary herbs
and other Applewood specialties.

All of our members who are familiar with Ruth Ashton
Nelson’s wild flower identifications books will be delighted
to know she too will be present with her new book, Plants
of Zion National Park. It promises to be another “must” for
anyone interested in this area and its flora.

Many of the illustrators will be present also and
although Anne Bliss and Ann Zwinger cannot attend, their
books will be available for purchase.

It promises to be quite an affair so remember 2 to
4 p.m. June 17 in Horticulture Hall. All are welcome.

JUNE CLASSES

Members should have the Summer List of Classes in
their hands by now and will note that many opportunities
are provided to enjoy living in Colorado.

Those of you who were Johnny-on-the-Spot and signed
up for How to Use a Botanical Key will really enjoy the
field trips to follow for you will understand taxonomic
vocabulary and concepts. Dr. Wingate has limited her class to
12 so that all may identify plants rather than depend on
someone else. Bring a hand lense and Rocky Mountain Flora
and come on June 14 to Classroom A at 9 A.M. Free.

Scheduled field trips include a chance to visit the new
unit of the Gardens on June 11, the Walter S. Reed
Botanical Garden in Upper Bear Creek. Travel Highway 74
to Evergreen (through Bergen Park or through Evergreen).
Take the lower fork at Upper Bear Creek Inn near Evergreen
Lake. Follow this Upper Bear Creek Road about 5 miles and
turn right at sign to Mt. Evans Elk Management Area and
Jefferson County Lab. School. The Reed Arboretum is about
1/2 mile beyond turnoff. Two stone pillars mark the
entrance. Meet there at 9:30 a.m., or if you prefer drive up
with a group that will meet at 8 a.m. at 909 York Street.
Mrs. Velma Richards and other members of Around the

Seasons have been studying the plants of this area for several
years. Please sign up after May 27. Limit 20.

Dr. Brunquist will lead his regularly scheduled trip on
June 16. Meet at 909 York Street at 9 a.m. Bring lunch. All
welcome .

Join the crowd on June 19 at 8 a.m. at the Gardens for
a trip to Colorado Springs, or meet us at 9:15 a.m. at the
Native Garden of the Demonstration Garden of the Horti-.
cultural Arts „ Society. This is located at the intersection of
Mesa Road and Glen Avenue in Monument Valley Park.
Take 1-25 to the Uintah Exit, turn left under 1-25 and the
railroad to Glen Avenue where you turn right for about two
blocks to Mesa Road. As a special treat, Lucian Long, who is
leading the trip, expects to take the group up the Old Stage
Road and show Cypripedium calceolus, Yellow Lady’s
Slipper. This plant is rarely seen for as Dr. Weber says, it has
almost been exterminated by wild flower “lovers”. Limit 30.
No sign ups before June 4, please. Free.

Different flowers will be seen as the tundra on Mt.
Goliath is the next area to be visited. Meet at 8 a.m. at the
Botanic Gardens House or at 9 a.m. at Echo Lake Lodge on
June 21. Dress warmly for often we can expect a storm at
that altitude. Limit 20.

Have you wondered how the Zoo attempts to control
insect populations in the new aviary? Since the birds can’t
be removed chemical sprays cannot be used; therefore,
biological controls may be the answer. Mr. Keenan, who is
helping them with this problem, will show slides and
describe some effective methods of control. Meet at 9 a.m.
in Classroom C on June 5. Free and all welcome.

Finally, students under 21 years of age will want to join
Dr. Feucht for the next classes in the NJHA program. On
June 18 at 909 York and June 29 in Classroom A, both at
9:30 a.m. Summer Characteristics of Woody Plants will be
discussed. Free.

The following is a list of shade and ornamental trees planted
at the Denver Botanic Gardens this spring.

Acer saccharum ‘Green Mountain’

A. platanoides var. schwedleri
A e scu lus glabra
Amelanchier laevis

Betula papyrifera

B. pendula var. tristis

B. pendula ‘Youngii’

Carpinus caroliniana
Celtis occidentalis
Cercidiphyllum japonicum
Cercis canadensis ‘Pink Charm’

Chionanthus virginicus
Cotinus coccygria ‘Velvet Cloak’

Crataegus crus-galli

C. lavallei

C. viridis ‘Winterking’

Eucommia ulmoides
Euonymus europaea
Fagus riversii

Fraxinus americana ‘Autumn Purple’

F. pennsylvanica var. lanceolata ‘Summit’

Ginkgo biloba

Gleditsia triacanthos var. inermis ‘Skyline’

Gymnocladus dioicus
Hamamelis japonica
H. mollis
H. virginiana
H. vemalis

Juniperus chinensis ‘Ketleeri’

Larix decidua
Malus ‘Beverly’

M. ‘Dorothea’

M. floribunda
M. ‘Katherine’

M. ‘Liset’

M. ‘Mary Potter’

M. ‘Radiant’

M. ‘Red Jade’

M. ‘Snowdrift’

M. ‘Tina’

M. ‘Van Gaurd’

M. zumi var. calocarpa
Myrica pensylvanica
Nyssa sylvatica
Ostrya virginiana
Phellodendron amurense
Philadelphus ‘Silver Showers’

Picea englemanni var. glauca
P. omorika

P. pungens var. glauca ‘Hoopsi’

Picea pungens ‘Mission’

Pinus cembra
P. nigra

P. strobus var. fastigiata
P. strobus var. nana
P. sylvestris
Populus sargentii
Potentilla ‘Jackmanni’

Prunus ‘Hally Jollivette’

Pseudotsuga taxifolia

Pyrus calleryana ‘Bradford’ /

Sophora japonica ‘Regent’

Sorbus aucuparia
Ulmus camperdownii
Viburnum burkwoodii
Viburnum X carlcephlum

Members probably have read of the end of the 56 year
old search by Burpee’s for a white marigold. On August 28,
1975 David Burpee paid $10,000 to a home gardener, Mrs.
Alice Vonk, of Sully, Iowa.

In its search for the White Marigold, the Burpee
Company has dealt with some unusual correspondence. One
gardener wrote: “If anything should happen to me before I
win the money, I want it to go to the Soldiers Home, not
my son”. Another hopeful gardener said: “If you get some
white marigold seeds from someone in my town, they will
be my seeds. I had the plant marked and my neighbor stole
the seeds because they are all gone”. Burpee did receive
seeds from a neighbor.

This payment to Mrs. Vonk makes the White Marigold
the costliest flower in the world. In addition to the $10,000
payment, the cost of Burpee research and of running the
trials to test thousands of hopeful entries from gardeners has
totalled more than $250,000.

For a follow-up story on this plant, see Horticulture,
February 1976.

Burpee Seeds

AND MORE ABOUT SEEDS

And if you are interested in another plant with a most
unusual color, Goldsmith Seeds, Inc. has announced a big
break-through with a really bright yellow petunia. The new
variety is appropriately named Summer Sun. Over ten years
of breeding work were required to produce this striking new
color.

Summer Sun belongs to the multiflora or “many
flowered” class of petunias. A dozen plants will produce
hundreds of 2 inch clear yellow flowers with deeper golden
yellow lines. Summer Sun looks best when planted in a large
bed for mass color effect of when combined with a contrast¬
ing color such as deep blue. Although individuals flowers are
not as large, nor plants quite as vigorous as other hybrid
petunias, Summer Sun makes a striking display. Plants are
available this spring in most stores where bedding plants are
sold or seeds can be ordered from Burpee or Park catalogs.

When dealing with seeds, remember “An optimistic
gardener is one who believes that whatever goes down must
come up”. Leslie Hall.

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YOU DID IT AGAIN!

The Helen Fowler Library is richer by $3,976.09 and
it’s all because you responded to our need for books for the
Sale and then came io see what others had contributed, and
bought, bought, bought. We’re really grateful to you and so
will be all the people who will use the many volumes your
money will add to the Library collection over the coming
year. Those of you who are supporting us for the fourth
time know that all the money which is raised through this
book sale is earmarked only for the purchase of new
acquisitions to the Library collection. To the newcomers,
welcome, and remember that we collect all year long for the
sale and we’ll look forward to seeing all of you again next
year, Really, thanks.

THE DENVER BONSAI CLUB will present its annual
exhibition of trees in miniature at the Denver Botanic
Gardens, Saturday, and Sunday, June 19th and 20th, from
10 a.m. to 5 p.m. daily.

Over 100 trees ranging in age from several months to
300 years old will be on display at this popular show, with
demonstrations to be presented each day.

The public is cordially invited to attend.

JUNE LOBBY COURT

Coming in the June Lobby Court display will be some
gesneriades including gloxinias, streptocarpus, and achimenes
and calceolarias, primulas and ranunculus. All this leads up
to a begonia display later in the month.

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HAWAIIAN ORCHID FILM

A free film on Hawaiian orchids will be shown on June
12 at 1:30, Classroom C. It is a color film and will last
approximately 30 minutes. So if you are interested in
orchids or are planning to visit Hawaii, be sure to attend.

A BIG THANKS!

A big thank you for Joan Fransen and other volunteers
who spent time and effort in contributing to making plant
sale ’76 a big success. Thanks again, we couldn’t have done
it without you!

SUMMER GUIDE SCHEDULE

This summer tours will be scheduled for the months of
July and August, starting at 10:00 a.m. on Tuesday, Wednes¬
day and Thursday. This change has been made so that the
Botanic Gardens can accommodate the children that are in
the year-round school programs.

Also a thank you to Bev Hanselman who has done an
excellent job in scheduling the tours — she is turning over
her position to Glin Duxbury.

Memorial Gifts have been received in honor of:

Mrs. David F. Hall
Mrs. Isabel T. Peel
Mr. Howard H. Sidwell, Jr.

Green Thumb Newsletter is published monthly by Denver Botanic Gardens,
Inc., 909 York Street, Denver, Colorado 80206. The Newsletter is included as a
benefit of membership in the Denver Botanic Gardens, regular membership dues
being $10.00 a year. Items for publication are welcome. The deadline for copy
to the editor is 2:00 p.m. on the 10th of each month preceding publication.
Editor — Margaret Sikes, 297-2547, Ext. 23.

GreeJ) Thumb Newsletter DENVER BOTANIC GARDENS, INC.

Copyright 1976

NO. 76-7 JULY 1976 TELEPHONE 297-2547

GARDENING TIPS FOR JULY

July may seem to be a strange time to talk about spring
and as delightful as our spring was this year, it is possible to
witness spring all over again and beat the heat at the same
time.

Spring is just now beginning at the timberline areas of
the Colorado Rockies and now is a good time to view the
colorful display of spring flowers in such places as Trail
Ridge, Loveland Pass, or better yet, the Mount Goliath
Alpine Trail on Mount Evans. It is possible during July to
view more than 50 different kinds of alpine flowers in
bloom. Along the Mount Goliath Trail you will also find a
group of picturesque bristlecone pine, some of which have
been dated to being at least two thousand years old.

The spectacular bloom along the trail must be seen to
be appreciated. Be sure to take protective clothing because
sudden storms, even rain, sleet and hail, may occur despite
the fact that it is July. To assist you in identifying the
plants you may wish to take along a book entitled, “Meet
the Natives” by M. Walter Pesman. This book is available at
the Denver Botanic Gardens bookstore. A guide of some of
the more common flowers is available in mimeograph form
by simply calling 355-8306. In the interest of preserving the
flora and tundra, please be careful to stay on the trail so
that all the beauty can be enjoyed for generations yet to
come.

Care of Bug-Chewed Plants

An extremely dry May and a caterpillar-ridden June has
left its toll in our gardens. To help your trees and shrubs
recover from defoliation caused by caterpillars, give them a
feeding using either a deep root method or a foliar feeding
with a totally soluble fertilizer designed for that purpose.
Several types are available such as Ra-Pid-Gro, Stern’s and
Morgro Liquid. Be sure to dilute according to directions for
foliar feeding. Too much can cause injury; too little does not
do an adequate job. A foliar feeding, of course, can only be
done when there is sufficient foliage on the plant to absorb
it. I have seen some trees and shrubs so badly defoliated that
root feeding is the only possible method. The idea is to help
boost the nutrition of the plant early enough in the season
so that it can develop some growth to carry it into the
winter months. Most defoliated trees and shrubs will also
show a surprising recovery.

If the top of your spruce trees was lost this year from
tussock moth damage, do not prune it out. Frequently, new
growth develops from “reserve” buds once the caterpillars
have been eliminated.

Spider Mites

This is the month to look out for infestations of spider
mites. An easy way to look for them is to hold a piece of
white paper beneath a branch and vigorously shake the
branch over the paper. If mites are present you will be able
to see them crawling on the paper. Presence of numerous
webs is also a sign of mites. They will also leave a
salt-and-pepper or stippled pattern on the leaves caused by

their feeding. Mites can be controlled by the use of Kelthane
or Chlorobenzilate.

Vacation Care

If you plan to be away for a vacation this month be
sure to include your yard in the planning. Get rid of all the
pesky weeds ahead of time and take care of the major insect
control problems before leaving. It is best not to ask a
youngster to do these chores. If you have someone taking
care of the lawn make sure to leave instructions on the
watering with particular attention to areas that need spot
watering because of peculiar soil problems. Lawn mowing is
very important. If possible, have the person use your own
mower, adjusted to the proper height of cut. A lawn can be
very badly damaged by a lawn mower set too low or not
properly sharpened. Be sure to point out all the hazards to
be looked out for such as sprinkler heads and high spots.

Vegetable Pests

Begin to look for signs of the tomato horn worm now
and take appropriate action when they are visible. Sevin does
a good job in controlling them but if you have only a few
plants you can pick the worms off by hand. Sevin will also
control the Mexican bean beetle, potato beetle and most
other foliar-feeding insects in your vegetable garden. It will
not, however, give good control of leaf miner in spinach,
beets, or chard. Malathion and Diazinon give reasonably
good control. If you use Diazinon be sure to allow for the
14-day waiting period before harvesting. The use of the
wrong pesticide in vegetable crops renders them useless. Most
systemic insecticides cannot be used on vegetables.
Chlordane is no longer recommended, being banned by the
EPA, but if you are having problems with soil-borne insects
like cutworms or wireworms, use Sevin instead. Isotox and
similar formulated insecticides, while designed for general
purpose on trees and shrubs, are not suitable for edible
crops. Be sure to check the label before using. If not
indicated for edible crops, don’t use it for that purpose.

J. R. Feucht

*******

A Regional meeting of the American Association of
Botanical Gardens and Arboreta will be held at *he Denver
Botanic Gardens from July 15 — 18th. All sorts of entertain¬
ing and educational events have been planned for our guests,
including a slide show on Colorado Wildflowers by Loraine
Yeatts; a tour of Summit Lake and Mt. Goliath, with return
by way of Central City; talks by George Kelly, Larry Watson
and A1 Rollinger on Rocky Mountain horticulture and
landscaping with native plants; a discussion of “Water Prob¬
lems in Bermuda” by Andrew Pierce and on “Southern
Arizona Plants Used in Landscaping” by Hubert L. Earle.
The final banquet will feature Dr. Howard Reynolds, who
will present an illustrated talk on “Plants Along the Trans-
Siberian Railroad”.

Members of the western region of AABGA will be in
attendance at this exciting conference.

JULY CLASSES

WHY DID ALL-AMERICA ROSE SELECTIONS INTRO¬
DUCE ITS 1977 AWARD WINNING ROSES IN JUNE

1976?

Many people are puzzled by the AARS procedure of
presenting its award winning roses to the public long before
plants of those varieties are obtainable at rose nurseries and
garden centers.

This question of “why” was put to George Rose
(actually an old Scottish family name) Director of Public
Relations for AARS. He explained that AARS wants the
public to be able to preview the new award winners prior to
their being offered for sale by the commercial growers.

To make that possible AARS has accredited some 114
of the larger public rose gardens throughout the United
States as being well maintained and well patronized by the
public.

Plants of the new award winners are sent to each of
these gardens in the spring preceding the year of their
introduction. For example, plants of the 1977 winners were
sent to the accredited public gardens at their planting
seasons in the early spring of 1976. The winners are ‘First
Edition,’ a plant with true floribunda growth habit and
luminous coral flowers; ‘Double Delight’, one of the most
outstanding hybrid teas produced in many years. This has
creamy white buds which open to disclose large areas of
carmine red along the edges of the petals. With the maturing
bloom, the red areas merge so that the flower appears to be
a red rose; ‘Prominent’ is a brilliant, hot orange gran diflora
winner which is particularly outstanding for use as a cut
flower.

With the June announcement of these winners, people
interested in roses are enabled to see them as actual bloom¬
ing plants by going to the closest of the 114 accredited
gardens. There they can judge for themselves the worth of
these roses long before they are ever offered for sale. The
Denver Botanic Gardens received ‘Double Delight’ of the
winners and this has been planted near the Herb Garden and
the Pylons.

Lists of the Accredited Public Rose Gardens are avail¬
able without charge from George Rose, Director of Public
Relations, All-America Rose Selections, P.0. Box 218,
Shenandoah, Iowa 51601.

Field trips will fill the month of July, as we all head to
the hills to enjoy nature! A reminder may be due: One of
the most convenient books to carry (and easiest to use) is
Meet The Natives by Walter Pesman. This book keys plants
by color and by altitude and is available in the Gift Shop.

July 8 join the group on Mt. Goliath. Meet at 8 a.m. at
909 York Street or at 9 a.m. at Echo Lake Lodge. Bring
lunch. Limit 20; no signups before June 24, please.

July 20th will find 20 visitors in Auraria, the old section
of Denver. Dave Luebbers, the leader of the group, is
currently writing a report of the work of Landscape Com¬
mittee of Historic Denver at this site so the trip should
prove to be interesting both horticulturally and historically.

Since parking is very difficult in that area, perhaps it
would be fun to make this a bike ride. That would make it
easier to get around and more in keeping with the period!
Ninth Street is between Champa and Curtis on the south
side of Cherry Creek. Meet the group there at 8:30 a.m. or if
you wish to car pool, at 8 a.m. at 909 York Street. Limit
20; no sign-ups before July 8, please.

Back to the mountains on July 21 when the regularly
scheduled Wednesday trip will journey to Mrs. Shepherd’s
cabin above Bailey. Please meet at 909 York Street at 9 a.m.
Bring lunch. All welcome.

A similar area to the above will be visited on Saturday,
July 24. Camp Freeman is property owned by Colorado
Womens College and Miss White, a biology professor from
CWC, will lead the group. Meet at 8 a.m. at 909 York or at
9 a.m. at Shaffers Crossing. Take 285 West. Bring lunch.
Limit 20. No sign-ups before July 9, please.

As a special treat, Dr. Denham will lead a trip to see
tundra plants on Loveland Pass! This is scheduled for July
17. Meet the group at the Arapahoe Forest Service Visitors
Center at the Mt. Evans Exit of 1-70 in Idaho Springs at
8:30 a.m. Bring lunch and remember to include liquids for
that altitude can be very dehydrating. The limit is 20 people
so call now if you wish to attend.

Reminder for all field trips —

If you are signed up but can not attend, please be
courteous enough to call and cancel so your space may be
given to someone else!

*******

The National Junior Horticulture Association program
will feature a class on Annuals on July 9. This is free and
open to students under 21 years of age. Meet at 9:30 a.m.,
Classroom A.

Finally two opportunities will be provided to learn
about saving the bounty of your vegetable garden. Canning
and Freezing Garden Produce will be taught on either
Tuesday, July 27 at 9 a.m. in Classroom B or if the evening
is more convenient, on July 28, at 7 p.m. also in Classroom
B. Free.

*******

From Flower and Garden comes this information: Scotts
will identify lawn weeds for you if you send a dry, complete
specimen tightly wrapped in aluminum foil to:

Scotts Weed — Ident
Marysville, Ohio 43040

They will answer in a few weeks with the name of the plant
and suggestions for its control. There is no charge and no
obligation.

“SPRING TAPESTRY”

watercolor by Wilma Stapleton

The Colorado Watercolor Society will have its Fifth
Annual All Watermedia Exhibition in the Botanic Gardens
Horticultural Hall from Thursday, July 8, through Wednes¬
day, July 21. Show hours are 10 a.m. to 4:30 p.m. daily.

All the paintings are for sale and approximately seventy
framed paintings will be on display with smaller unframed
works available. Members of the group are active in the art
community of Denver and exhibit frequently in shows
throughout the state.

Juror for this exhibit will be Rob Gratiot, art teacher at
the Emily Griffith Opportunity School.

Solange Gignac, librarian, Helen Fowler Library,
attended the annual meeting of the Council on Botanical and
Horticultural Libraries co-hosted by Longwood Gardens and
the Philadelphia Horticultural Society. The C.BJJ.L.
members decided to initiate a pilot program involving record¬
ing of lists of plants, seed and nursery catalogs of particular
regions. Local catalogs published, printed, distributed before
1920 are of particular interest. Should you have any old
catalogs, local or not local, please consider giving them to
the library or allowing your holdings to be recorded. These
catalogs are historically valuable because they may be the
only record of plant introductions to a particular region.
Please call Solange Gignac, librarian, at 297-2547, Ext. 24, if
you would like to participate in this program.

THOUGHTS FOR THE FOURTH

Gardening in 1776 was strenuous ... no high analysis
plant foods, no convenient garden center for the latest in
plants or chemical, and no power tools. Elaborate seed
catalogs were uncommon in the colonies and newspaper
announcements of the arrival of shipments of seeds were
written in a style that could politely be described as
imaginative.

Eastern settlements, mostly clustered along navigable
streams or on the coast line were hemmed around by forests
that sheltered birds and wild beasts of all kinds.

Among the common folk, gardening was geared mostly
to producing food and herbs. Flowers might be limited to
one or two kinds to brighten the doorway.

Only around the older towns was gardening a genteel
pastime. The colonies did have an economic and social elite
and they patterned their flower and herb gardens after the
elaborate European fashions of the day. Good gardeners
were scarce and high wages were paid to lure English and
Scottish landscape designers and gardeners.

At least two of the Founding Fathers were keen
gardeners. George Washington wrote:

“The more I am acquainted with agricultural affairs, the
better I am pleased with them; insomuch, that I can
nowhere find so great satisfaction as in those innocent
and useful pursuits. In indulging these feelings, I am led
to reflect how much more delightful to an undebauched
mind is the task of making improvements on the earth
than all the vain glory which can be acquired from
ravaging it . . .”

Thomas Jefferson thought:

“No occupation is so delightful as the culture of the
earth, and no culture comparable to that of the garden.
Such a variety of subjects, some one always coming to
perfection, the failure of one thing repaired by the
success of another, and instead of one harvest a con¬
tinuing one through the year.”

A helpful suggestion from the Avant Gardener is that
house plants might enjoy a summer vacation, too. Most
tropicals, with the exception of African violets and
other gesneriads, can be put outside. Some such as philo¬
dendron, rubber plants and dieffenbachia will need pro¬
tection provided by a covered porch, breezeway or lath
house. Other kinds may enjoy the brightest light
available.

Be sure to check your light intensity, watch your
plants to see how they are responding and remember to
acclimatize them by gradually moving them out. Do the
same when they are ready to return inside in the fall.

ROCKY MOUNTAIN BROMELIAD SOCIETY

An organizational meeting will be held at the Denver
Botanic Gardens, in classroom ‘B’, on July 14th, 1976 at
7:30 p.m.

Larry Mason, Scientific Editor of the Journal of the
Bromeliad Society will demonstrate techniques of proper
care and propagation of Bromeliads.

Mr. Mason has published a series of articles on the
evolution of Bromeliads.

For information call Lawrence Mason 233-0577

or Paul Earle 757-8825

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TERRACE AND GARDEN TOUR
(July 22 - Thursday, 10 a.m. - 6 p.m.)

The annual Terrace and Garden Tour will take place
Thursday, July 22, between the hours of 10 a.m. and 6 p.m.
Eight very special gardens in the Cherry Hills Village and
Greenwood Village areas will be featured this year. The
gardens are:

1. Mr. and Mrs. Robert McCammon
3461 South Cherry

2. Mrs. Doris Vickers
2 Sunset Drive

3. Mr. and Mrs. H. J. Bleakley
35 Sunset Drive

4. Mr. and Mrs. Jerry Bayless
4737 South Lafayette

5. Mr. and Mrs. Ron Lundquist
1 East University Lane

6. Mr. and Mrs. William Thurston
5205 South Steele

7. Barbara and William Thulin
5505 South Steele

8. Mrs. Mary Mead
5555 South Steele

The price of the tickets will be a $5.00 donation to the
Denver Botanic Gardens. Tickets may be purchased at the
Conservatory Gift Shop (297-2348), from any Botanic
Gardens’ Guild member, or the first and last gardens on the
day of the tour. Iced tea and cookies will be available in the
Thulins’ garden, with its lovely view of the mountains.
Among the features of interest in the gardens chosen this
year are swimming pools in natural settings, bonsai arrange¬
ments, orchid culture, and vegetable gardens. The gardens are
well grouped so that driving is easy and tickets contain a
map giving directions to each garden.

“Heritage of Splendor” is the title of the film to be
shown on July 10th at 1:30 p.m., Classroom C. The camera
follows Americans as they enjoy the forests, mountains,
parks and beaches and records their littering of both public
and private property. Trash only becomes trash after it has
first served a useful purpose. It becomes litter only after
people thoughtlessly discard it. As taxpayers we pay dearly
and in many ways for this messy habit. There is a bit of
humor and some magnificent photography of our great
scenic splendors. All welcome.

LOBBY COURT

Tuberous begonias, one of the public’s favorite displays,
will be featured in the Lobby Court in July. We always
receive many favorable comments about these glorious
blossoms, so plan to visit and admire them then.

A donation earmarked for the Lobby Court has been
received in memory of Hazel Moore. Thank you so much.

A special weekend is planned on July 24-25 from 9 to
5 p.m. At this time the daylilies will be at their best and
members of the Hemerocallis Society will be on hand
in the outside garden to answer all your questions about
these lovely flowers. Printed information as to care
and suggested varieties will be available also so plan
to come, admire, and learn.

$100.00 REWARD FOR RETURN OF PHOTOGRAPHIC
EQUIPMENT TAKEN FROM THE MYCOLOGY LAB. NO
QUESTIONS ASKED. CALL 297-2547 X 7.

90209 OaVHOlOO H3AN30 • 133H1S >1H0A 606

ONI SN30HV9 OINVIOO U3AN3Q

9Z6L Ainr

Green Thumb Newsletter is published monthly by Denver Botanic Gardens,
Inc., 909 York Street, Denver, Colorado 80206. The Newsletter is included as a
benefit of membership in the Denver Botanic Gardens, regular membership dues
being $10.00 a year. Items for publication are welcome. The deadline for copy
to the editor is 2:00 p.m. on the 10th of each month preceding publication.
Editor — Margaret Sikes, 297-2547, Ext. 23.

Greel) Thumb Newsletter DENVER BOTANIC GARDENS, INC.

Copyright 1976

NO. 76-8 AUGUST 1976 TELEPHONE 297-2547

GARDENING TIPS FOR AUGUST

Tomato worms, mites and thrips are the creatures we
should watch out for this month. As a matter of fact, mites
and thrips are already in high gear on quite a wide variety of
plants in the home grounds.

Perhaps you have noticed the “hummingbird moths”
flying around your garden in the evening hours. This rather
interesting and colorful moth, while feeding on the nectar of
your flowers, is also laying eggs on your tomato plants. They
are the adult stage of the tomato horn worm. The eggs are
large enough to be visible, but the moth usually lays them in
cleverly disguised places. Soon the eggs will be hatching and
the young caterpillars will begin their voracious feeding.

It is always surprising how fast a tomato worm can grow
and how much he can eat. The worms also seem to eat more
while a gardener is on vacation than when at home. At the
first sign of feeding, apply Sevin at the manufacturer’s
recommended rate. If you are going to be away, make an
application of Sevin just before departing in order to give
protection until your return. The earlier you control it the
less pesticide needed and the less frequent applications. Be
sure to apply to the lower leaf surfaces as well as the upper.

If you prefer not to use chemicals, pick off the worms,
at least on a weekly basis. Some kids enjoy doing this and
could be rewarded with a nickel a worm or whatever you
choose to pay. There are, however, two disadvantages to this
method. First, you generally have to wait until the worms
are big enough to be readily visible. By that time they have
already done the damage. Second, a few worms always seem
to escape the eye, particularly in dense tomato plantings that
are not staked and are sprawling on the ground.

Spider mites are eight-legged creatures which are not
actually insects. They are tiny, thus often escaping detection
until plant damage has occurred. In evergreens such as
Pfitzer junipers, the damage will first be noticed as an
off-color of the plant, appearing almost as if it is drying up.
Heavy infestations will result in a complete browning of the
plant. On broadleaf plants, spider mite infestations take on a
“salt-and-pepper” effect or a stippled look to the leaves.
Severely infested leaves will turn brown and dry up.

Spider mite control is not difficult to achieve because
there are excellent miticides available. The one most readily
available is Kelthane. This chemical is especially designed to
have sufficient residual to catch the hatching young as well
as stop the adults.

For those who do not wish to use miticides or any type
of chemical control, a method that has proven somewhat
satisfactory for reducing mite populations is to syringe the
plants frequently with a strong stream of water. There are,
however, disadvantages to this method. The strong stream of
water may reduce mite populations but it may also severely
damage flowers. '

Thrips are even smaller than mites and are quite evasive,
making detection and control a bit difficult. Thrips are
responsible for damage to rose buds, frequently preventing
them from opening properly. When the buds do open, they
are very much distorted. Thrips also feed on a wide variety
of garden flowers. Damage from thrips on foliage is usually a

silvering effect. This is caused by the thrips sucking out
plant juices from the cells; the empty cell cavities then take
on a silvered appearance.

One of the thrips’ most favored woody plants is the
privet hedge. A heavily infested hedge will suddenly have a
silvery look, followed by browning. If not controlled,
defoliation will occur. Control of thrips is also relatively
simple, particularly for those that feed on the foliage.
Malathion, applied in 2-3 sprays spaced about seven days
apart, will generally do the job. For those thrips affecting
the flower buds of roses, a systemic insecticide may be
needed. These should be used with caution. An overdose will
be harmful to the roses.

Watering continues to be a problem, especially in lawns.
One of the greatest difficulties is the spots of heavy clay soil
or “clay lenses” which don’t seem to take up water readily
and dry to a hard-packed surface in a short period of time,
particularly in 90° weather. This situation cannot be
improved by adding more water. As a matter of fact, adding
more often accentuates the problem by cutting off the air
from the root system and further compacting the soil. The
solution is to aerate. This subject was covered in previous
Green Thumb gardening tips but should be repeated. For
small areas, a hose-attached soil needle will do the job but it
would be very time-consuming for large areas. For the latter,
rent a drum aerator. Before using it, however, be sure the
soil has some moisture in it. Water a few days prior to
renting the machine. The machine does not work well in a
muddy soil which has been recently watered nor does it
work well on a hard clay.

The practice of watering frequently as a result of the
hot weather has also caused stress in trees and shmbs in the
lawn area. In many ways, trees and lawns are not com¬
patible. While trying to satisfy the watering requirements of
the lawn, you can easily overwater (under-oxygenate) the
root zone of your trees and shmbs. The most severely
affected are those species that are accustomed to a gravelly,
well-drained soil such as pines and firs. Swamp species like
cottonwoods and willows can tolerate this better. If you
have a sprinkler system, either change the heads that are
near the trees and shmbs to divert the water away from
them, or close them off entirely and hand water the trees
and shmbs as needed. Watering trees with a soil needle is a
good method in that it does some aeration at the same time.
Be sure to angle the needle away from the tree — not into

Dr. J. R. Feucht.

Question Time

How many of our members can name the patron saint
of gardeners? St. Fiacre, born in the late 500s, was an Irish
hermit who lived in County Kilkerry. After numerous
disciples disturbed his solitude there, he moved to northern
France. He established a monastery at Meaux and became
famous for his curing of diseases, his ascetic life, and his
daily labor in the garden. Appropriately enough he is always
represented with a spade. His saint’s day is August 30th.

AUGUST CLASSES (and more)

The regularly scheduled field trip led by Dr. Brunquist
will meet at 909 York Street at 9:00 A.M. on August 18th.
All welcome.

N. J. H. A. participants can do no better than to attend
County Fairs to learn about vegetables. There one may see
all sorts of unusual plants like celeriac, New Zealand spinach,
and witloof, besides the best possible examples of more
common ones. If the judges have time they can explain what
they use as criteria when awarding ribbons. In fact all ages
may very much enjoy attending a Fair; often there are rodeo
events, animal exhibits, plus clothing and food displays
besides the fruits and vegetables to be seen.

A miniature one, the Denver County 4-H Fair, will be
held on August 4th and 5th at the Horticulture Hall of
Denver Botanic Gardens. Some of the scheduled events are:
Introduction of the Fair King and Queen (10:30 AM), 4-H
In Action Booths (11 AM), Exhibits on display (2-9 PM), all
on August 4 and on August 5, the Awards Program (2-4 PM)
and Dress Review (7:30 PM). Come and have fun.

An overall review for the N.J.H.A. students will be held
at 9:30 A.M., August 23rd in Classroom A. This is an
opportunity to prepare for the State Contest on September
18th.

Also on August 23 rd, Mrs. Kosanke will begin her class
on Techniques of Collecting and Drying Flowers in Silica
Gel. The class will meet at 9:00 A.M. in Classroom B and
Mrs. Kosanke will take her students outside to select flowers.
Please bring two plastic shoe boxes with lids, scissors, wire
cutters, and a wide mouthed gallon plastic container with a
tight lid. On Friday, August 27th, the second day of the
class, the group will also meet at 9:00 A.M., Classroom B.
The cost of this class is $17.50. Limit 18.

The last field trip of the session to Mt. Goliath is
scheduled on August 24th. Meet at 8:00 A.M. at 909 York
Street, or at 9:00 A.M. at Echo Lake Lodge. Free. Limit 20.
No sign-ups before August 9th, please.

A Herb Garden Walk will be led by Gloria Falkenberg
on August 25th. Meet at 8:00 A.M. in the Herb Garden
(near 909 York). Many herbs have historical connotations
that date from classical times. Winners in the Pan Hellenic
Games in Greece were crowned with parsley and Galen
wrote that parsley was “sweet and grateful to the stomach”.
Virgil recommended in the Georgies “All about let there be
luxuriant growth of green Cassia and wild Thyme with its
spreading perfume and abundance of strongly scented
Savory”. Limit 20. Free.

Also on that date Basic Mushroom Identification, a
six-week class, will be offered by George Grimes. It is
co-sponsored by the Colorado Mycological Society and the
Denver Botanic Gardens from August 25 to September 29
from 7 to 9 P.M. in Horticulture Hall. The fee is $10.00.

People interested in this subject should also plan to
attend the Mushroom Fair, which the Colorado Mycological
Society will sponsor on Sunday, August 22nd in the west
end of the Museum of Natural History and the Bailey
Lounge. Since members of CMS will have taken a foray prior
to the Fair, many examples will be on display and members
will help identify samples that the public bring in. Colored
slides of Colorado mushrooms will be continually shown and
mushroom books will be available for purchase as will a
cookbook written by Mycological Society members.

Many exhibits will be featured including spore prints,
artistic treatment of mushrooms in crafts, and a demon¬
stration by personnel from Denver General Hospital on
treatment of mushroom poisoning.

The Mushroom Fair will open at Noon and extend into
the afternoon. The cost is $1.00 for those over 12 years old.
Free for those younger.

And More About Mushrooms!

A lovely Mushroom Book has been presented to the
Helen Fowler Library by Dr. Alexander H. Smith. This
illustrated portfolio, a limited printing, includes life sized
color illustrations of 15 species. Number 34 of this special
printing of 75 is on display in the Rare Book Room.

Please remember due to the popularity of some courses
and limited enrollment, it is very possible that a class may
be filled early. If this happens, please do not be discouraged
since it is likely that the popular courses will be repeated at
a later date.

A Rose Judging School for the Rocky Mountain
District will be held in Horticulture Hall at Denver
Botanic Gardens on August 14 and 15th. Although the
school is directed toward those people interested in
becoming Accredited Rose Judges, it will be of value to
anyone wanting to leam more, about roses in depth.
Subjects covered will include Rose Anatomy, Identifica¬
tion of Varieties and Practice in Judging. On August 14th
registration is at 8:30 and the school begins at 9:00 a.m.
August 15 will primarily cover review, practice and the
test. The cost is $5.00 for instruction and $10.00 for
those taking the test for credit. For additional informa¬
tion please call Mrs. Herb Franson, 424-3942.

Members have been inquiring about the activities going
on to the north of the Education Building. Twenty two
advanced students in the Youth Garden have been busy
indeed at that spot. First came intensive soil preparation,
then soil analysis, followed by the circular plot design. The
sprinkler system has been installed and the exterior land¬
scaping of the Garden will soon follow. The students have
been working with the French Intensive Gardening System
and also will try some hydroponic experiments. Two College
Interns, Anita Hall from Colorado State University and Judy
Golden from the University of Northern Colorado have been
most helpful in all aspects of design and planting and of
course the participating students have really been involved.

Come see for yourself and talk to these enthusiastic
gardeners. The garden is open on Tuesday and Thursday
from 8:30 to 11:30 a.m. and 5 to 7:30 p.m. and on
Saturday from 1 to 4 pan.

Of course, walk across the street and see the other
Children’s Garden and drive over to 29th and Jackson where
the Barrett Garden is really growing too.

Are you getting surfeited with zucchini? How about

adding variety to your menu
cake?

Take 3 Cups grated Zucchini

3 Cups Sugar

1 Cup Chopped Pecans
\lA Cups Oil or
1 Cup Crisco

4 Eggs beaten

by fixing that vegetable in a

3 Cups Flour (may add
dash of cinnamon
or nutmeg)

2 t. Baking Powder
1 t. Soda
A t. Salt

DENVER BOTANIC GARDEN TRIP
TO GREAT BRITAIN

By Lucian Long

Those of us who have just returned from Great Britain
wish to report that we couldn’t have had a better time. We
arrived for the opening day of the Chelsea Flower Show
where no effort was spared to make this the greatest flower
show in the world.

From that moment on there was a succession of events
which completely filled the 23 days with exciting
adventures. We traveled about 2,000 miles with our own
coach and tour guide, and in addition, we were favored with
the expert guidance of Mr. T. H. Findley, gardener to the
Queen. Through Mr. Findley’s intimate knowledge of British
flora and his experience of having worked in many of the
important gardens of England and Wales we were able to see
the best of each in the least time. Each garden contained its
own surprise. As we rounded a bend in Sheffield Park
Garden we came upon a grove of hardy palm trees from
China which were planted in 1911. I found a native wild
orchid in one of the meadows. At Bodnant Garden in Wales
the famous Laburnum Arch was at its peak glory.

Each park seemed to abound with fuchsias, azaleas,
magnolias, and rhododendrons in immense clumps inter¬
spersed among fine old oaks, rare maples, majestic junipers
and cedars, and sweet chestnuts, many several hundred years
old. There were trees and shrubs from all parts of the world
including the pink- flowering dogwood from the eastern
United States, the California big sequoias, cypresses from
S.E. United States, and a Colorado blue spruce. In Kew
Gardens we located a clump of Colorado columbine.

At Hampton Court we saw the oldest grape vine in
Britain which is still producing grapes. It is from a cutting of
the Black Hamburg variety and has attained a girth of
seventy -eight inches. It was planted in 1768 presumably by
Lancelot Brown, a famous gardener who was destined to
transform the crowded, geometric gardens of the day into
English park gardens, with their hills, lakes, and trees. We
saw many examples of his influence.

Altogether we visited 24 gardens including a few which
have only recently been opened to the public because they
were too large for the exclusive resources of one family.
Also we were privileged to visit Chartwell, the home of
Winston Churchill and to see beautiful landscaping and the
chair where he sat in meditation by the pool.

Not all our time was spent visiting gardens, but included
stops for historic cathedrals, Roman baths, walled cities,
castles, and palaces. We drove under the Newport Arch, the
only Roman gateway remaining in Britain which spans a
main road, although we had to close the coach ventilators in
order to clear. To complete the span we saw the prehistoric
monuments of Stonehenge and Avebury, dating back to
about 1200 B.C. Certainly it was a trip we will remember
forever.

DAHLIA SHOW
AUGUST 28 - 29

Combine squash, sugar, oil and eggs. Beat well. Sift dry
ingredients and add to mixture. Add nuts. Grease and flour
13” x 9” baking pan and add mixture. Bake at 350°F. for
one hour or until done. (This recipe is courtesy the
Childrens’ Garden where lots of zucchini is grown!)

Tuberous begonias of all colors from white to pink,
rose, red, apricot, flame orange and salmon graced the
Lobby Court area in July and will continue as display plants
in August. Be sure to see these spectacular blooms (and
other begonias, too!)

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If you are interested in becoming a volunteer, what
about serving in the Library? There are at present 32
volunteers at the Helen Fowler Library, Denver Botanic
Gardens. The volunteers are involved in numerous and varied
duties which include: processing new acquisitions; yearly
inventory of book collection; typing subject headings and
classification number on Library of Congress cards; classifi¬
cation and cataloging of pamphlets; maintenance of
periodicals file; filing LC cards; maintenance of cross
references for public card catalog; circulation; bookkeeping;
writing to government agencies for publications; keeping up
the plant clinic records; maintenance of seed and nursery
catalog collection; original cataloging of books for which LC
cards are not available; producing stencils listing current
book and pamphlet acquisitions; looking up call numbers for
monthly accessions list; overdues; reading shelves; preparing
books for binding; reading book reviews; preparing catalog
cards for duplication; checking pamphlet file subject
headings; searching current literature for possible additions
to library collection; helping patrons, keeping daily tally,
collecting and recording fines, explaining and accepting new
memberships.

In the past large endeavors such as reclassifying the
collection to the Library of Congress classification scheme,
checking the entire periodical collection and the annual book
sale have been done by volunteers. During the past five
years, the library services have increased by 500 per cent.
Services could not be provided to the patrons and staff
without the cooperation of the library volunteers.

Sounds like fun? Call Solange Gignac, 297-2547 Ext. 24
for further information on ways you can help!

August Film

A beautiful film about the fantastic flowers of South
Africa will be shown on August 14th at 1:30 P.M., Class¬
room C. The award winning film, “On the Third Day” shows
such beauties as proteas and gerberas, many filmed at
Kirstenbosch Gardens.

Denver Rose Society’s
Annual Rose Show

The Denver Rose Society will hold its annual rose show
August 22, 1976 at Denver Botanic Gardens (Horticulture
Hall), 1005 York Street. The colorful roses will be on
display to the public from 1:00 p.m. to 5:00 p.m. There is
free admission and parking.

Judging of the roses will be in the morning, 10:00 a.m.
to 12 noon, with over 175 classes of roses including a special
division for people wishing to show roses who have never
done so before (Novice and Juniors). Members of the Denver
Rose Society will be available to help these people enter a
rose in the show. There will also be classes for artistic
arrangements and table settings using roses. Twenty seven
different trophies will be awarded and will be on display at
Horticulture Hall.

Those wishing to enter roses should have them available
by 9:00 a.m. No rose entry will be accepted after 10:00
a.m.

Anyone having questions may contact Dr. Warren
Kirkley, chairman of the rose show, 424-0472.

Green Thumb Newsletter is published monthly by Denver Botanic Gardens,
Inc., 909 York Street, Denver, Colorado 80206. The Newsletter is included as a
benefit of membership in the Denver Botanic Gardens, regular membership dues
being $10.00 a year. Items for publication are welcome. The deadline for copy
to the editor is 2:00 p.m. on the 10th of each month preceding publication.
Editor — Margaret Sikes, 297-2547, Ext. 23.

GjJdSJ) ihUIUb NoJtffkffcr DENVER botanic gardens, inc.

Copyright 1976

NO. 76-9 SEPTEMBER 1976 TELEPHONE 297-2547

GARDENING TIPS FOR SEPTEMBER

Where did the summer go? Seems just yesterday that I
wrote in this column about getting your gardens ready for
spring but perhaps we’ll still have some summer left and
hopefully, an Indian summer with an extended growing
season.

The weather is always so unpredictable in the fall and as
weather records indicate, a killing frost can come early in
September or may not occur until as late as November. The
average is sometime around mid -October.

If you think this has been an unusually buggy and hot
year, you are right but checking back in the records that are
kept in this office, I find the types of problems encountered
parallel the 1974 season. In that season too, we encountered
an early warm-up spring, an unusually hot spell in June and
July and rain squalls in August.

Perhaps the greatest difference seen this year was in the
amount of foliage-type diseases which are unusual for the
semi-arid west. This can be blamed to a great extent on the
wind damage that occurred in mid-June when trees were in
full leaf. The wind damage which caused a lot of bruising of
foliage allowed easy access for fungi and certain bacteria.
Fire blight, a bacterium, was again a big problem this season.
There is still no satisfactory control for fire blight.

Another difference that was encountered this year was
the number of mature trees that failed to leaf out or did leaf
out only marginally and then faded away. In most cases, it
was blamed on insufficient soil moisture during the winter¬
time. In any case, it occurred in deeply rooted trees as a
result of a nearly complete deficiency of moisture in the
subsoil areas. Many of these trees also showed a basal rot
development which weakened them and in some cases, even
a moderate wind was sufficient to blow them over.

This experience again points up the importance of deep
root watering during open, dry winters. Deep watering is also
a good idea in the fall, after the leaves begin to develop their
fall color. It is best not to do it before then, however,
because it might promote some late growth.

Fall Lawn Care

September is a good time to prepare a new lawn or
patch up an old one. Lawns had a tough time this season
with many diseases as well as drought injury. If you have
areas in an old lawn that never seem to fill out well or died
as a result of disease, you may wish to overseed with a good
bluegrass variety. It is important to buy a good quality seed
that is free of weeds. Before seeding the area, loosen the soil
or roughen it up so that the seed will lodge properly and
then use the thatch that is raked out of the area as a
temporary seed cover. This will help reduce the need for
frequent watering. You can also patch in some areas using
pieces of sod taken from the edge of the lawn, particularly
where edging is necessary to stop the lawn from creeping
into your flower beds or other gardens.

If you are doing an entire new lawn, whether you seed
or sod, it is important to prepare the soil so that it will not
compact. If the soil is fairly heavy you will need to add up

to three cubic yards of peat, old barnyard manure or other
similar matter to help keep the soil open. About one inch of
organic matter on the surface will be equivalent to three
cubic yards per 1,000 square feet. The organic matter should
be thoroughly tilled into the soil to a depth of at least six
inches.

This is a good time to also gain control of weeds in the
lawn. Since lawn grasses do most of their side growth (tiller¬
ing) in the fall, you can do much towards weed control by
promoting this growth with fall fertilization. A 20-10-5
analysis fertilizer used at double rate, that is, twice the rate
indicated on the bag, will help develop a good, strong turf
and will help it to remain strong through the winter months
and well into next spring. Be sure when using the fertilizer
that it is watered in immediately after application. To avoid
streaking in the lawn, run the spreader in two different
directions. The rotary-type spreaders will spread the material
more evenly and much faster.

Dandelions and other broadleaf weeds that are in the
lawn can also be successfully controlled at this time of year
using 2, 4-D or similar mixtures of broadleaf weed control
chemicals. Controlling the weeds now will reduce the need
for future weed control next spring. I prefer to do spot
treatment using a “Killer-Kane” because it requires less use
of chemicals, puts it where it belongs, and reduces chances
of spray drift injury. This method would not be practical,
however, if you have a lawn that is covered with weeds. In
this case, it is better to use a regular pressure sprayer which
has an adjustable nozzle that will produce coarse droplets. If
you use a sprayer for weed control, be sure to mark it
permanently for weed control only. Most of the broadleaf
weed killers cannot be completely washed out of the sprayer
and the residue can cause damage to your trees, shrubs and
flowers if the same sprayer is used later with insecticides and
fungicides.

Fall Planting

To plant a tree or shrub in the fall has always been
controversial, particularly, in Colorado. The reason for the
controversy is that it is impossible to predict sudden changes
in the weather that can cause injury to newly planted trees.
If you contemplate planting any trees or shrubs this fall,
consider using a mulch over the root zone which will tend to
delay freezing of the soil and will help to promote better
rooting before cold weather sets in. If this is done, many
trees will survive the winter without any problem at all. In
most cases, deciduous trees and shrubs will survive better
from fall planting than will evergreens. This is because the
transpirational surface is lost when the leaves fall but
evergreens continue to lose moisture and if we have cold,
dry winds, they will lose moisture faster than the roots,
damaged through transplanting, can replace.

If you insist on planting evergreens in the fall, in addi¬
tion to mulching the soil surface and giving them a
thorough, deep watering, you can protect from possible wind
injury by temporarily wrapping them with burlap or, con-

(Continued inside page)

sider using an antitransparent which is sprayed on the
foliage. Anti transparents are chemicals which put a film over
the foliage surface and temporarily protects most of the
moisture loss through the stomates (breathing pores) in the
leaves. Antitransparents, however, must be used with caution
because if they are applied too strong they can smother the
plant and they should never be used during freezing weather.

Fall Bulbs

Now is a good time to look for and purchase any
spring-flowering bulbs that you will need to plant this fall.
The earlier you purchase them, the more likely you will be
to find a good selection of both size, variety and those in
top condition. When selecting your bulbs, find the largest
size of that type or variety. Check them carefully and
discard those that have mold or mechanical damage.

Where possible, try to purchase your bulbs from garden
centers that have them in open bins rather than in pre¬
packaged containers. This will give you a better chance to
inspect them carefully.

The only danger with the open-bin type of marketing is
that sometimes the bulbs are mixed. That is, a customer may
not put them back in the proper bin. Usually, however,
bulbs of your variety will be slightly different in color, shape
or size than another. The bulbs can be planted now but if
you are too busy, there is nothing wrong with waiting until
October. In the meantime, make sure the soil you plan to
plant them in is well prepared and well drained.

Dr. J. R. Feucht

NEXT LOBBY COURT DISPLAY

Remember last fall’s magnificent display of chrysanthe¬
mums in the Lobby Court? They will be back again in
September, replacing the unusual begonia display of the late
summer. This time there will be about 200 plants in a blaze
of all the brilliant fall colors — yellow, gold, orange and red,
and later the purple ones.

The chrysanthemums, now being prepared in Botanic
Gardens greenhouses, will demonstrate the popular plant and
flower forms of bonsai, cascade, spray and standard in ten
different flower types: exhibition incurve, recurve, reflex,
decorative, feathered or laciniated, spider and quill,
anemone, spoon, single and semi-double, pompom and
button.

BOTANIC GARDENS GLAD
WINS AT GREELEY SHOW

A fine gladiolus, planted and grown in Botanic Gardens
by Bob Folsom, and shown at the Northern Colorado
Gladiolus Show by Lee Ashley under the name of Denver
Botanic Gardens, was the winner of “All America Little
Champion,” “Section Champion” and “Little Champion
Spike— 1976” ribbons.

The spike, “Lambkin,” a 200 class miniature white,
introduced this year by Carl Fisher of St. Charles, Minn, was
grown here in the All-America display garden. The Northern
Colorado show was held in Greeley on August 7.

******

A most welcome addition to the Helen Fowler Library
is the copying machine that was installed in August. The
cost per copy is 10 cents.

SEPTEMBER CLASSES & TRIPS

The educational program for September offers a variety
of experiences for all ages. While a few field trips will be
available, several classes ranging from Chrysanthemum
Culture to Food in History are offered.

Beginning August 25, Mr. George Grimes will be teach¬
ing his Basic Mushroom Identification course. Mushroom
identification can be a fascinating and fulfilling hobby. The
class will consist of illustrated lectures and will include dis¬
cussions of the life cycle, anatomy and physiology of mush¬
rooms. It will be held on Wednesdays, August 25 through
September 29 from 7:00 to 9:00 PM. in Horticulture Hall.
While there is no limit to class size, there will be a $10.00
fee. If you do have an interest in the mushrooms, be sure to
see the Mushroom Book by John Cage, Lois Long and Dr.
Alexander Smith in the Waring Rare Book Room. It is an
excellent appreciation of the color, diversity and folklore of
the mushrooms.

Dr. E. H. Brunquist will lead a Plant Identification Field
Trip on Wednesday, September 15, for those who enjoy
identifying the flora of the nearby mountains. The group
will meet at 9:00 a.m. in the parking lot of Botanic Gardens
House. Any adult may come along; there is no limit on the
number. Bring a sack lunch. Gasoline expenses will be shared
with the driver. This is the last of these trips for the year.

Two other field trips offered this month are both on
Saturday, September 18, at 9:00 a.m. A field trip to Adams
County Nature Preserve will be under the guidance of Jim
Ratzloff. The group will first meet in Classroom C to view
slides on the area and its flora in all seasons before driving
out to the site. Jim has done an in-depth study on the area
and will be able to provide abundant information on the
fifteen acres along the Platte. Bring your lunch. Transporta¬
tion by car pool. Limit 20.

JIM RATZLOFF TO B.L.M.

Jim Ratzloff, who will lead the September 18th field
trip to Adams County Nature Preserve, has been working
this summer for Botanic Gardens, collecting specimens of
cultivated plants, both woody and herbaceous, for the
Herbarium. Jim is leaving us now and will be working
through Jefferson County C.E.T.A., making a list of plants
in the Montrose area for the U.S. Bureau of Land Manage¬
ment. He will be particularly concerned with identifying
endangered species of plants and his results are to be used in
environmental impact statements. Jim is a graduate of Metro¬
politan State College with a bachelor’s degree in biology.

DENVER BOTANIC GARDENS
CALENDAR OF EVENTS
SEPTEMBER, 1976

SEPTEMBER

1)*

7:30 a.m.

Education Building - Horticulture Hall

“Keep Colorado Beautiful” (Registration)

1)

7:00 p.m.

Education Building - Horticulture Hall

Basic Mushroom Identification -

Instructor: Mr. George Grimes

2)*

8:00 a.m.

Education Building - Horticulture Hall

“Keep Colorado Beautiful”

2)

7:00 p.m.

Education Building - Lecture Room “C”

Colorado Open Space Council

2)*

7:45 p.m.

Education Building - Horticulture Hall

Denver Orchid Society

3)

11:00 a.m.

Botanic Gardens House - Main-Dining-Kitchen

Civic Garden Club

4)

9:30 a.m.

Botanic Gardens House - Main Room

Gloxinia Gesneriad Growers

7)*

10:00 a.m.

Education Building - Herbarium

Herbarium Committee Meeting

7)*

1:00 p.m.

Botanic Gardens House - Dining Room

Editorial Committee Meeting

7)

7:30 p.m.

Education Building - Lecture Room “B”

Denver Bonsai Club

8)*

9:30 a.m.

Botanic Gardens House - Main Room

D.B.G. Guild Meeting

8)

10:00 a.m.

Education Building - Lecture Room “A”

“The Urban Vegetable Garden”

Instructor: Mr. Larry Latta

8)

7:00 p.m.

Education Building - Horticulture Hall

Basic Mushroom Identification

Instructor: Mr. George Grimes

8)*

7:30 p.m.

Botanic Gardens House - Dining Room

Landscape Industry Council

9)*

9:00 a.m.

Education Building - Lecture Room “B”

“Chrysanthemum Culture”

Instructor: Mrs. Nancy Collins

9)

7:30 p.m.

Botanic Gardens House - Main-Dining-Kitchen

Denver Rose Society

10)

7:30 p.m.

Botanic Gardens House - Main-Dining-Kitchen

Denver Dahlia Society

11)*

9:00 a.m.

Education Building - Horticulture Hall

Children’s Garden Graduation

11)

1:30 p.m.

Education Building - Lecture Room “C”

Film: “Carnations a Mile High”

13)*

9:30 a.m.

Tour of Outside Gardens - Instructor: Mr. Glenn Park

13)

7:30 p.m.

Botanic Gardens House - Main Room

Denver Sierra Club (Wildlife Committee)

13)

7:30 p.m.

Education Building - Horticulture Hall

Colorado Mycological Society Meeting

14)*

9:30 a.m.

Education Building - Lecture Room “A”

Sunburn & Blisters Garden Club - Meeting and Tour

14)*

4:00 p.m.

Botanic Gardens House - Dining Room

Executive Committee Meeting

14)*

7:30 p.m.

Education Building - Horticulture Hall

E.C.C. Nature Study Unit

14)

7:30 p.m.

Education Building - Lecture Room “B”

Sierra Club

15)*

8:30 a.m.

Education Building - Horticulture Hall

Keep Colorado Beautiful - Meeting and Buffet

15)

9:00 a.m.

Botanic Gardens House - Parking Lot

PLANT LIFE FIELD TRIP - Dr. E. H. Brunquist

15)

10:00 a.m.

Education Building - Lecture Room “A”

‘The Urban Vegetable Garden”

Instructor: Mr. Larry Latta

15)*

1:00 p.m.

Education Building - Lecture Room “C”

Tropical Plants of the Conservatory

Instructor: Mrs. P. Hayward

15)

7:00 p.m.

Education Building - Horticulture Hall

Basic Mushroom Identification

Instructor: Mr. George Grimes

15)

7:30 p.m.

Education Building - Lecture Room “B”

Sierra Club

16)

7:30 p.m.

Education Building - Lecture Room “A”

Colorado Open Space Council

16)

7:30 p.m.

Education Building - Lecture Room “C”

Organic Garden Club

17)*

7:30 p.m.

Education Building - Lecture Room “B”

Colorado Bonsai Club

17)

7:30 p.m.

Education Building - Herbarium

Denver Botany Club

18)

All day

Education Building - Horticulture Hall

National Jr. Horticulture Society

18)*

9:00 a.m.

Education Building - Lecture Room “B”

Art Workshop for Children

Instructor: Ms. Diane Lewis

18)

9:00 a.m.

Education Building - Lecture Room “C”

Slides: By Mr. Jim Ratzloff and Field Trip to
Adams County Nature Preserve

18)

9:00 a.m.

Meet at 909 York Street

Field Trip to Study Dye Plants

Instructor: Ms. Carol Hoffman

CALENDAR OF EVENTS FOR SEPTEMBER (Continued)

18)

9:00 a.m.

Botanic Gardens House - Main Room

Hi-Country Judges Workshop — Mrs. Doreen Fussell

18)

1:30 p.m.

Education Building - Lecture Room “B”

Art Workshop for Children

Instructor: Ms. Diane Lewis

20)*

9:30 a.m.

Education Building - Lecture Room “B”

Central District of President’s Council

20)

7:30 p.m.

Education Building - Lecture Room “B”

Rocky Mountain Bromeliad Society

21)*

10:00 a.m.

Education Building - Lecture Room “B”

Basic Bonsai — Instructor: Mrs. Mary Neil

21)

7:30 p.m.

Education Building - Horticulture Hall

Sierra Club

21)

7:30 p.m.

Education Building - Lecture Room “B”

Denver Bonsai Club

21)

7:30 p.m.

Botanic Gardens House - Main-Dining-Kitchen

Rocky Mountain African Violet Council

22)*

9:15 a.m.

Education Building - Horticulture Hall

Jr. League — Environmental Program

22)

10:00 a.m.

Education Building - Lecture Room “A”

“The Urban Vegetable Garden”

Instructor: Mr. Larry Latta

22)*

1:30 p.m.

Education Building - Lecture Room “C”

Tropical Plants of the Conservatory

Instructor: Mrs. P. Hayward

22)

7:00 p.m.

Education Building - Horticulture Hall

Basic Mushroom Identification

Instructor: Mr. George Grimes

23)

7:30 p.m.

Education Building - Lecture Room “B”

Capitol Hill United Neighborhood

23)*

7:30 p.m.

Botanic Gardens House - Main-Dining-Kitchen

Denver Men’s Garden Club

24)

9:00 a.m.

Education Building - Horticulture Hall

Potter’s Guild Juried Show

OPEN TO PUBLIC: 9:00 a.m. - 5:00 p.m.

25)

9:00 a.m.

Education Building - Horticulture Hall

Potter’s Guild Juried Show

OPEN TO PUBLIC: 9:00 a.m. - 5:00 p.m.

26)

9:00 a.m.

Education Building - Horticulture Hall

Potter’s Guild Juried Show

OPEN TO PUBLIC: 9:00 a.m. - 5:00 p.m.

27)

9:30 a.m.

Botanic Gardens House - Main Room

Ultra Violet Club

27)

7:30 p.m.

Education Building - Lecture Room “A”

Nature Conservancy

27)

7:30 p.m.

Education Building - Lecture Room “B”

Sierra Club (Wilderness Workshop)

28)*

10:00 a.m.

Education Building - Lecture Room “B”

Basic Bonsai - Instructor: Mrs. Mary Neil

28)*

4:00 p.m.

Botanic Gardens House - Conference Room

Board of Trustees Meeting

28)

7:30 p.m.

Education Building - Lecture Room “C”

Gladiolus Society Meeting

29)

All Day

Gift Shop Closed for Inventory

29)

10:00 a.m.

Education Building - Lecture Room “A”

“The Urban Vegetable Garden”

Instructor: Mr. Larry Latta

29)*

1:30 p.m.

Education Building - Lecture Room “C”

Tropical Plants of the Conservatory

Instructor: Mrs. P. Hayward

29)

7:00 p.m.

Education Building - Horticulture Hall

Basic Mushroom Identification

Instructor: Mr. George Grimes

30) 6:00 p.m.

OCTOBER

Education Building - Lecture Room “A”

“Food in History” - Instructor: Mrs. Eileen Price

1)

Education Building - Horticulture Hall

Denver Orchid Society Show - OPEN TO PUBLIC

1)

1 1 :00 a.m.

Botanic Gardens House - Main-Dining-Kitchen

Civic Garden Club Meeting

2)

9:00 a.m.

Library

Use of the Library

2)

Education Building - Horticulture Hall

Denver Orchid Society Show - OPEN TO PUBLIC

2)

9:30 a.m.

Botanic Gardens House - Main Room

Gloxinia Gesneriad Growers

3)

Education Building - Horticulture Hall

Denver Orchid Society Show - OPEN TO PUBLIC

*Members or Enrollees Only

For those interested in natural dyes, the second field
trip of the day will be centered around the Identification
and Color Properties of Dye Plants. The group will meet
with Carol Hoffman at Botanic Gardens House at 9:00 a.m.
There will be $1.50 fee for the trip.

Different areas of plant cultivation can be explored by
attending any of several classes offered this month. Although
many people believe that the coming of cold weather brings
an end to work in the outside' garden, Larry Latta’s class,
The Urban Vegetable Garden, will show you what should be
done now to prepare for your spring garden. The course will
explore the whys, hows and whens of city plot gardening.
The class will meet on Wednesdays, September 8 to October
13 at 10:00 a.m. to Noon in Classroom A. There will be a
$10.00 fee.

If you’ve had it with toiling in the soil, try
Hydroponics. Norton Novitt is a firm believer in the
bubbling water method of growing plants. He is teaching the
class at his home so that you may see the equipment,
methods and results first hand. The class will be held on
Saturday, September 11 at 9:00 a.m. Call 297-2547 for
directions to Mr. Novitt’s home. There is a $1.00 fee for the
class.

For those of you who like a challenge, classes in bonsai
and chrysanthemum culture are on the agenda for this
month. On Thursday, September 9, Mrs. Nancy Collins will
demonstrate the proper way to shape Chrysanthemums for
desired effects. Especially successful varieties for this area
will be suggested. It will be held 9 - 11:00 a.m. in the
greenhouse. Limit 12.

Basic Bonsai, under the direction of Mrs. Mary Neil, will
teach the fundamental techniques of wiring, pruning, water¬
ing and potting. A $12.00 fee is required and will cover the
soil and wire. Additional materials will be at the student’s
expense. The class will meet on Tuesdays, September 21 -
October 12 in Classroom B from 10 - 12:00 Noon. Limit 15.

In a different vein, Eileen Price will explore the rise and
fall of civilizations along with the spread of plants. Every
Thursday from September 30 through October 28, Food in
History will meet from 6:00 to 7:30 p.m. in Classroom A.
The cost of this class is $10.00.

If anyone is interested in learning more about the
Botanic Gardens, this is your month. On Monday, September
13, Mr. Glenn Park, Assistant Director of the Denver Botanic
Gardens, will take a group on a leisurely walk through the
Outside Gardens. He will point out the many improvements
made this summer and discuss plant material and landscape
design. Meet at 909 York Street at 9:30 a.m. Limit 20.

A GUIDE TO HAPPINESS

Learn the fascinating story and histories of the Passion¬
flower, Norfolk Pine, Bullhorn Acacia, and the many other
tropical plants. Be amazed at the many uses of the Palm
Trees.

Every week see the beauty of the blooming plants, trees,
and shrubs in the conservatory. Get a feel of Hawaii right
here in Colorado.

Watch a youngster’s eyes light up at his first sight of a
“real” banana growing on a banana plant.

Receive a letter of gratitude like this one:

“Thank you for being our guide. I liked the jungle.

I liked the way the bananas grow. The flower that

looked like a bottle brush. I liked the African Tulip.

I liked the smell of the lime leaf. Thank you.

Yours Truely,

Cindy Stout”

Enjoy the tropical teas and other guide activities.

Receive the physical satisfaction derived from sharing
your knowledge of the many tropical plants with others.

Enroll in the Tropical Plants of the Conservatory course
beginning Wednesday, September 15.

Join the Denver Botanic Gardens Associates.

BECOME A DENVER BOTANIC GARDENS
CONSERVATORY GUIDE!

Interesting features of the plants in the Conservatory is
the topic of Tropical Plants of the Conservatory, which is
offered and taught by The Associates. Although the class is
designed to prepare interested people to be tour guides, the
class is open to anyone. The $25.00 fee will be refunded to
those students who guide for a total of forty hours. Mrs. Peg
Hayward will be the instructor. The class will meet Wednes¬
days, September 15 - November 3 from 1 - 3:00 p.m. in
Classroom C and the Conservatory. Limit 20.

Ms. Diane Lewis, Director of the Canaan Center for
Creativity in Denver, is offering an Art Workshop for
Children on Saturday, September 18. Youngsters who like to
paint may express their creativity with the color and shapes
found in the plant life at the Gardens. Any child in grades 1
- 3 is welcome. Materials will be provided. Grades 1 - 3 will
meet from 9 - 12:00 Noon. This session will meet in Class¬
room B. There will be a $1.50 fee. Limit 10 students.

The Tree Walk in Washington Park, conducted by Dr.
Gambill, was so popular last year that it is necessary to limit
the attendance this year to 25 persons. It will take place on
Saturday, October 2. The group is to gather at the South
Marion Street Parkway entrance to the north end of
Washington Park at 9:00 a.m. Call in to make your
reservation.

LIFE MEMBERSHIP

A Life Membership in Denver Botanic Gardens has been
established by Mr. E. H. Honnen on behalf of his wife,
Mamie Honnen.

Mrs. Honnen, a beloved member and worker, is an
honorary life trustee of the Gardens. It was she who under¬
wrote the original Garden Fair and Show which became the
Denver Garden and Home Show, and she was instrumental in
starting the annual Plant Sale.

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CHILDREN S GARDEN GRADUATION

The York Street Children’s Garden Graduation will be
held on September 11 at 1:30 P.M. in Horticulture Hall.
Certificates will be awarded to all children who have com¬
pleted the program successfully. There are 42 advanced
gardeners and 55 beginner gardeners. The children will
present original skits and poems about their gardens and
what they mean to them. Refreshments will be served after
the ceremony at the youth garden located North of the
education building. All are invited to tour the new youth
garden during the open house which will be held at this
time.

FREE FILM ON CARNATIONS

Colorado carnations are famous all over the country. To
learn more about the big business of growing them here you
should see the free film, “Carnations A Mile Hi,” which will
be shown at Botanic Gardens, Classroom C, on September
11th at 1:30 P.M. The film was prepared for Colorado
Flower Growers.

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SHOW OF POTS FOR HORTICULTURE

Colorado Potter’s Guild’s first juried show will display
only those pots designed for horticultural uses. The show
will be held in Horticulture Hall on September 24, 25 and
26, and will be open from 9 a.m. to 5 p.m. each day.

Clay media pots, including terra cotta, glazed and un¬
glazed, stoneware and porcelain, in a variety of shapes and
forms, will be seen. There will be hanging pots, large and
small pots for plants, pots for flower arrangements and con¬
tainers for dried arrangements.

Gene Lang, well known in this region, will jury the
show, insuring the highest quality of exhibits.

All pots on display will be for sale, unless indicated
otherwise. A donation of 50% will be given to Botanic
Gardens at the end of the show.

Refreshments will be served during show hours.

Memorial gifts have been received in honor of Mrs.
Margaret Mead and Mrs. Helen S. Beise; also a northern
red oak tree to be planted in the Hammer Garden in
memory of Eleanor Van Schaack Knowles.

The botanical stamp collection at the Library is being
brought up to date. Since the gift of the Kathryn Kalmbach
stamp collection in 1972, many stamps have been donated
and allowed to accumulate. Clifford Schaffer, a Library
volunteer and amateur philatelist, has undertaken this
project. The collection of botanical stamps — American,
foreign, cancelled or not cancelled — is a continuing Library
activity. Should anyone wish to donate time and/or stamps
to the Library, please call Solange Gignac at 297-2547, Ext.
24.

Green Thumb Newsletter is published monthly by Denver Botanic Gardens,
Inc., 909 York Street, Denver, Colorado 80206. The Newsletter is included as a
benefit of membership in the Denver Botanic Gardens, regular membership dues
being $10.00 a year. Items for publication are welcome. The deadline for copy
to the editor is 2:00 p.m. on the 10th of each month preceding publication.
Editor — Margaret Sikes, 297-2547, Ext. 23.

DENVER
BOTANIC
GARDENS, INC.

Green Thumb Newsletter

Copyright 1976

No. 76-10 OCTOBER 1976 297-2547

GARDENING TIPS FOR OCTOBER

PRESERVE GARDEN FLOWERS NOW

With fall fast approaching, it will not be too long before
many of the colorful flowers in your garden will be destroyed
by frost. You can continue to enjoy many of your garden
flowers by preserving them, as well as having fun preparing
them for dry arrangements.

One method of preserving garden flowers is drying them
by the borax method; using the borax as a medium to
support the plant and to help draw the water out of it.
Some prefer to use silica gel by itself or in combination with
borax. The equipment needed for drying flowers is about
twenty pounds of dry, sifted borax, cardboard cartons such
as milk cartons, or cheese boxes, or any other shallow
containers. The types of flowers that will dry the best
include zinnias, marigolds, dahlias and roses. The latter will
dry best if picked when the bud is only partially expanded
rather than fully opened. They tend to shrivel if picked
when fully mature. It is important to pick the flowers on a
day when the foliage and flowers are dry; picking only those
flowers that have just come into bloom and not fully
opened. Most flowers will continue to open somewhat during
the drying process. Normally, the foliage is removed from
the stems because foliage is not easy to preserve in a way
that it would have a good appearance.

To preserve flowers in borax, place about in the
bottom of the container, standing the flowers with the heads
upside down in the borax and gently working the powder in
the petals, making sure that you keep the petals smooth.
Keep working the powder around the flower heads until
they are completely covered but only enough to cover the
heads, not the stem. The containers are then placed in a
warm room away from direct sunlight. It is usually best not
to try to store them in the basement because there is a
tendency for the basement to have high humidity and this
condition will slow down the drying process and cause some
of the flowers to become moldy. Normally, it takes two to
three weeks for flowers to completely dry. When dried, the
flowers can be carefully removed from the borax and
cleaned with a soft dusting brush.

It is usually best to dry more flowers than you anti¬
cipate needing because some of them will be damaged
through the drying and cleaning process.

Since most of the dried flower heads will be stemless, or
have only short stems, in order to use them in an arrange¬
ment, you will need to make artificial stems with wire
covered with florist’s tape. Be sure to pick wire that will be
thick enough and strong enough to support the weight of
the flower heads.

Some garden flowers such as cockscomb (Celosia), straw
flowers, most ornamental grasses, and golden rod can be
dried without the use of borax by simply placing them in a
dark, dry, warm room. Darkness is essential during the

(Continued next page)

Love Those Volunteers !

Casual visitors may not know it but many of the people
they chat with when they tour the Gardens are volunteers.
The Gardens have a regular staff of 35, a small group for
such a big responsibility, and that is why the over 300
volunteers make such a difference. They serve in diverse
areas like Gift Shop, Guides, Hostess/Information Desk,
Library and Plant Sale besides chairing many standing com¬
mittees including Children’s Garden, Editorial, Herbarium,
and Library among others.

Once a year the whole group gets together at the
Annual Meeting of The Associates, scheduled this year for
October 18 in Horticulture Hall. The business meeting will
begin at 10:30 A.M. followed by lunch at 12:15. Mr. Charles
M. Drage, the guest speaker, will talk on Front Range
Gardening. He will give timely gardening hints for our area
and will allow ample time for questions. Mr. Drage, one of
the early contributors to The Green Thumb magazine is
eminently qualified to discuss such a wide topic for he
served as Jefferson County Extension Agent and more
recently as the state-wide Extension Horticulturist for Colo¬
rado State University. Since retiring from C.S.U. he now
writes as the Regional Editor reporting on the mountain
areas for Flower and Garden magazine.

Denver Orchid Society Annual Fall Show

Date: October 2, 9 AM to 4:45 PM (Saturday)

October 3, 9AM to 3 PM (Sunday)

Place: Horticulture Hall

The Denver Botanic Garden

1005 York Street, Denver

Purpose: To educate the general public about
orchids and their culture. To show accom¬
plishments of Denver orchid growers.
Special: A series of lectures and classes on orchids
and orchid culture Saturday, October 2,
9-12 at the Botanic Garden. Free and open
to the public.

FOR LIST OF ORCHID BOOKS SEE BACK PAGE.

drying process because sunlight will cause the colors to fade.
On such plants, if you are wanting straight stems, they
should be hung upside down, suspended from wires or
strings. For natural curves in the plants to use later on in
arrangements, dry them standing upright and the weight of
the flower head will cause the stem to bend in a natural
curve.

You need not be limited to garden flowers, even many
weeds can be used successfully for dry arrangements. The
seed heads of sorrel or dock, lambsquarter, amaranthus or
pig weed, and thistle and many other weeds make attractive
additions to a dry arrangement, particularly when combined
with garden flowers. Road sides and ditch banks are full of
all kinds of weeds that can add interesting decorations to
your winter bouquet.

Those wishing to preserve fall foliage such as the golden
colors in aspen will have better results by taking the
branches, mashing the stem bases with a hammer and
soaking them for several days in a mixture of one-third
glycerin and two-thirds water. After the foliage has taken up
the water-glycerin mixture, allow the plants to dry slowly in
total darkness. This will keep the colors from fading and the
glycerin keeps the foliage supple. Best results will be
obtained when collected from trees that have just changed
colors. If they are collected too late the leaves may drop off
in the drying process.

If you have grown gourds for decoration, they can be
enjoyed for many years if properly cured and cared for. It is
best to leave the gourds on the vine until they are fully
colored and mature; normally until they have been exposed
to a light frost. Cut off the mature fruit with the stem still
attached, avoiding mechanical bruising or scratching as this
will show up as an ugly scar after they have been cured.

After harvesting the gourds, wash them in soapy water
and rinse with clean water to which you have added a small
amount of household disinfectant (do not use bleach). This
will help control surface organisms that often cling to the
shell, causing discoloration and decay. Next, spread the
gourds out on several layers of newspaper in a warm, dry
place to let surface moisture evaporate. This helps harden
the skin and set the color. During the curing process, rotate
the gourds at least once a day. Curing usually takes about
one week.

To finish the curing process, place the gourds in a warm
but dark room for three or four more weeks and when the
gourds seem to be thoroughly dried, they may be coated
with wax, shellac or varnish. If wax is used, use a water-base
type wax such as that used on automobiles but one that
does not contain the cleaners. After waxing, they may be
polished with a soft cloth and displayed in any manner you
wish.

In order- to enjoy your garden the entire winter, start
searching now for things that can be preserved for future
decoration.'

Tips for Planting Bulbs

Last month we talked about how to buy bulbs and if
you have them purchased, now is a good time to put them
in the ground but good soil preparation is absolutely
necessary to ensure quality bloom.

The most important thing as far as bulbs are concerned
is proper aeration and drainage. Condition your soil as deep
as possible and where clay soils are involved, add coarse sand
and organic matter; thoroughly mixing it with your soil. To
do this properly requires very deep cultivation if you are
planning to use tulips, narcissus and other large bulbs.
Assuming that your soil is reasonably well-drained and
aerated, plant bulbs two inches deeper than recommended
by the charts usually available where you purchased your
bulbs. This will help to prolong the number of years that the
bulbs will give showy flowers because the deeper they are
planted, the less likely they are to self-propagate, that is,
splitting and producing bulblets; thus, avoiding overcrowding
for a longer period of time.

Planting them deeper also helps to prevent early
emergence of the bulbs in the spring which often results in
disappointments because of a late freeze which will damage
or kill the new shoots.

If you are planting bulbs in masses, the easiest way is to
dig all the soil out to the approximate depth for the
particular type bulb. Stir in a little bone meal or super
phosphate, set the bulbs to the proper depth and backfill
with your soil. This is usually a very strenuous job but it can
be very worthwhile in producing a mass of color the
following spring.

Another method of bulb planting is to use a special bulb
spade available in some garden supply and hardware stores.
Such spades will allow planting to about an eight-inch depth
which is generally acceptable for the larger bulbs. A planting
chart is available upon request by calling 355-8306.

Safe Storage of Pesticides

Now that the growing season is nearing an end, it is a
good idea to take an inventory of all your garden pesticides
and put them in safe storage. Many of the liquid pesticides
must be stored where they will not freeze during the winter
but they should never be stored in the home anywhere near
the kitchen or the heating plant. Most important, if you
have young children, store all pesticides where they cannot
get to them. The best way is under lock and key but simply
putting them on a high shelf is not appropriate.

If you have empty or near empty containers that had
pesticides in them, do not dump the unused portions down
the sink or in the toilet. Rather, dispose of all pesticide
containers through your normal trash collection. Any glass
containers should be first wrapped in several layers of
newspapers to prevent accidental breakage of these con¬
tainers before trash collection.

The simplest way to get rid of unused pesticides is to
use them according to the label for pest control.

Dr. J. R. Feucht

DENVER BOTANIC GARDENS

CALENDAR DF EVENTS

OCTOBER

OCTOBER, 1976

1)*

1 1:00 a.m.

Botanic Gardens House — Main-Dining-Kitchen

Civic Garden Club

2)

9:00 a.m.

Education Building — Horticulture Hall

Denver Orchid Society Show

OPEN TO PUBLIC: 9:00 a.m.-4:45 pan.

2)

9:30 a.m.

Botanic Gardens House — Main Room

Gloxinia Gesneriad Growers

3)

9:00 a.m.

Education Building — Horticulture Hall

★ ★★★★★★★

Denver Orchid Society Show

OPEN TO PUBLIC: 9:00 aan.— 3:00 pan.

★ ★ ★ ★ ★

5)*

10:00 a.m.

Education Building — Lecture Room “B”

Basic Bonsai — Instructor: Mrs. Mary Neil

5)*

10:00 a.m.

Education Building — Herbarium

Herbarium Committee Meeting

5)*

1:00 p.m.

Botanic Gardens House — Dining Room

Editorial Committee Meeting

5)

7:30 p.m.

Education Building — Horticulture Hall

East Denver Central Civic Association

6)*

10:00 a.m.

Education Building - Lecture Room “A”

“The Urban Vegetable Garden”

Instructor: Mr. Larry Latta

6)*

1:30 p.m.

Education Building — Lecture Room “C”

Tropical Plants of the Conservatory - Mrs. P. Hayward

6)*

4:00 p.m.

Botanic Gardens House — Dining Room

Chatfield Committee Meeting

7)*

1:00 p.m.

Botanic Gardens House — Dining Room

Associates Board Meeting

7)*

6:00 p.m.

Education Building — Lecture Room “A”

“Food in History” — Instructor: Mrs. Eileen Price

7)

7:00 p.m.

Education Building - Lecture Room “C”

Colorado Open Space Council

7)*

7:45 p.m.

Education Building — Horticulture Hall

Denver Orchid Society Meeting

8)

7:30 p.m.

Botanic Gardens House — Main-Dining-Kitchen

Denver Dahlia Society Meeting

9)

9:30 a.m.

Education Building — Lecture Room “A”

“Fruit Trees for the Area”

Instructor: Mr. Herb Gundell

9)

1:30 p.m.

Education Building — Lecture Room “C”

Film: “Wonders of the Wilderness”

9)

6:00 p.m.

Education Building — Horticulture Hall

★ ★★★★★★★

Colorado Native Plant Society Founders

Meeting — 6:00 p.m. Membership Enlistment

7:00 pan. Program

★ ★ ★ ★ ★

11)

7:30 p.m.

Education Building — Horticulture Hall

Colorado Mycological Society

ID

7:30 p.m.

Education Building — Lecture Room “A”

Denver Sierra Club (Wildlife Committee)

12)*

10:00 a.m.

Education Building — Lecture Room “B”

Basic Bonsai — Instructor: Mrs. Mary Neil

12)*

4:00 p.m.

Botanic Gardens House — Dining Room

Executive Committee Meeting

12)*

7:30 p.m.

Education Building — Horticulture Hall

E.C.C. Nature Study Unit

13)*

9:15 a.m.

Botanic Gardens House — Main Room

D.B.G. Guild Meeting

13)*

10:00 a.m.

Education Building — Lecture Room “A”

‘The Urban Vegetable Garden”

Instructor: Mr. Larry Latta

13)*

1:30 p.m.

Education Building — Lecture Room “C”

Tropical Plants of the Conservatory - Mrs. P. Hayward

13)

7:30 p.m.

Education Building — Lecture Room “A”

Landscape Industry Council

13)

7:30 p.m.

Education Building — Lecture Room “B”

Denver Commission on Community Relations

14)

6:00 p.m.

Education Building — Lecture Room “A”

“Food in History” — Instructor: Mrs. Eileen Price

14)

7:30 p.m.

Botanic Gardens House — Main-Dining-Kitchen

Denver Rose Society

15)*

7:30 p.m.

Education Building — Lecture Room “B”

Colorado Bonsai Club

15)

7:30 p.m.

Education Building - Lecture Room “C”

Denver Botany Club

16)

10:00 a.m.

Education Building — Horticulture Hall

★ ★★★★★★★

“Greening of Your Thumb” — Mr. Herb Gundell

★ ★ ★ ★ ★

CALENDAR OF EVENTS FOR OCTOBER (Continued)

18)*

10:00 a.m.

Education Building — Horticulture Hall

Associates Annual Meeting & Luncheon

Speaker: Charles M. Drage

18)

7:30 p.m.

Education Building - Lecture Room “A”

Rocky Mountain Bromeliad Society

18)

7:30 p.m.

Education Building — Lecture Room “B”

Sierra Club (Wilderness Workshop)

19)*

10:00 a.m.

Education Building — Lecture Room “B”

Intermediate and Advanced Bonsai

Instructor: Mrs. Mary Neil

19)

7:30 p.m.

Education Building - Lecture Room “B”

Denver Bonsai Club

19)

7:30 p.m.

Education Building - Horticulture Hall

Sierra Club (General Meeting)

20)*

10:00 a.m.

Education Building — Lecture Room “B”

“Unusual Container Plants”

Instructor: Mr. Andrew Pierce

20)*

1:30 p.m.

Education Building - Lecture Room “C”

Tropical Plants of the Conservatory - Mrs. P. Hayward

21)

6:00 p.m.

Education Building — Lecture Room “A”

“Food in History” — Instructor: Mrs. Eileen Price

21)*

7:00 p.m.

Education Building — Horticulture Hall

Mayor’s Advisory Council

21)

7:30 p.m.

Education Building — Lecture Room “B”

Colorado Open Space Council

21)

7:30 p.m.

Education Building — Lecture Room “C”

Organic Garden Club

22)*

9:45 a.m.

Education Building — Horticulture Hall

Ikebana International (Workshop)

23)

10:00 a.m.

Education Building — Horticulture Hall

★ ★★★★★★★

“Greening of Your Thumb” — Mr. Herb Gundell

★ ★ ★ ★ ★

25)

9:30 a.m.

Botanic Gardens House — Main Room

Ultra-Violet Club Meeting

26)*

10:00 a.m.

Education Building — Lecture Room “B”

Intermediate and Advanced Bonsai

Instructor: Mrs. Mary Neil

26)

7:30 p.m.

Education Building — Lecture Room “C”

Gladiolus Society Meeting

27)*

10:00 a.m.

Education Building — Lecture Room “B”

“Unusual Container Plants”

Instructor: Mr. Andrew Pierce

27)*

1:30 p.m.

Education Building — Lecture Room “C”

Tropical Plants of the Conservatory - Mrs. P. Hayward

28)*

10:00 a.m.

Botanic Gardens House — Main Room

Around the Seasons Meeting

28)*

6:00 p.m.

Education Building — Lecture Room “A”

“Food in History” — Instructor: Mrs. Eileen Price

28)*

7:30 p.m.

Botanic Gardens House — Main-Dining-Kitchen

Denver Men’s Garden Club Meeting

29)*

9:45 a.m.

Education Building — Horticulture Hall

Ikebana International (Workshop)

30)* 8:00 a.m.

NOVEMBER

Education Building — Lecture Room “B”

★ ★★★★★★★

Class for Denver Public School Teachers

★ ★ ★ ★ ★

2)*

10:00 a.m.

Education Building — Lecture Room “B”

Intermediate and Advanced Bonsai

Instructor: Mrs. Mary Neil

2)*

10:00 a.m.

Education Building — Herbarium

Herbarium Committee Meeting

2)*

1:00 p.m.

Botanic Gardens — Dining Room

Editorial Committee Meeting

3)*

10:00 a.m.

Education Building — Lecture Room “B”

“Unusual Container Plants”

Instructor: Mr. Andrew Pierce

3)*

1:30 p.m.

Education Building — Lecture Room “C”

Tropical Plants of the Conservatory - Mrs. P. Hayward

4)

7:00 p.m.

Education Building — Lecture Room “C”

Colorado Open Space Council

4)*

7:45 p.m.

Education Building — Horticulture Hall

Denver Orchid Society Meeting

5)

11:00 a.m.

Botanic Gardens House — Main-Dining-Kitchen

Civic Garden Club

6)

8:30 a.m.

Education Building — Lecture Room “B”

Class for Denver Public School Teachers

6)

9:30 a.m.

Botanic Gardens House — Main Room

Gloxinia Gesneriad Growers

*Members or Enrollees Only

OCTOBER CLASSES

Solange Gignac will conduct an orientation to the Helen
Fowler Library on October 2 at 9:00 a.m. with Use of the
Library. Free and all welcome.

On the same day Dr. Gambill will lead a Tree Walk in
Washington Park. Meet at the So. Marion Street Parkway
entrance at the north end of Washington Park at 9 a.m. Only
25 people can be accommodated, so get your name in now!

The Denver County Agent, Herb Gundell, will talk
about Fruit Trees for our Area on Saturday, October 9 at
9:30 a.m. in Classroom A. He will suggest varieties that have
proved successful in the Denver area and mention other
points to bear in mind when ordering or planting trees. Free.

Students who have completed Basic Bonsai with Mrs.
Neil may continue their initiation to this oriental art form
by signing up for Intermediate and Advanced Bonsai. The
class is from October 19 to November 9 from 10 to noon,
Classroom B. The cost of $12.00 includes soil and wire;
other materials will be at the student’s expense. Advanced
students will be responsible for bringing their own material.
Limit 15.

Finally, the Superintendent of the Conservatory,
Andrew Pierce, will teach an advanced house plant class
entitled Unusual Container Plants. This will be your oppor¬
tunity to learn about some more uncommon tropical and
subtropical plants. The fee is $7.50 and as of this writing,
there are 10 students in the class. Don’t delay in signing up
for only 10 more can be accepted.

LOBBY COURT

While the “pestilence stricken multitudes” are piling up
on your lawn, take a break from leaf raking and come admire
the chrysanthemums in the Lobby Court.

A donation in memory of John Scott has been received
for this Fund. Thank you very much.

Care to Share:

Unusual seeds, pods, dried blossoms and ornamental
grasses are needed by Around the Seasons for the Annual
Pre-Christmas Sale. Money plant is extremely popular, as
well as yarrow, allium, pods of okra, poppies, wisteria and
trumpet vine or sweet gum balls, cotton balls, acoms and
eucalyptus in variety and assortment of cones. Some osage
orange and ornamental gourds are also desirable.

Please bring to the Botanic Gardens House, 909 York St.
on October 28th before noon or call for further information.

SOIL RENOVATION AND RESTORATION PROGRAM
AT THE CHILDREN’S GARDENS

This fall will mark the beginning of a soil building
program for the York St. Children’s Garden, the Barrett
Garden, and the new Youth Garden.

We will begin the program with the collection of organic
materials which will be temporarily stored on the lot north
of the York St. Children’s Garden. (Enter the alley off 11th
Ave. between York and Josephine. Deposit organic material
at the North Fence.)

The Denver Botanic Gardens is enlisting volunteer help
now for the collection of bagged leaves and grass clippings
which can be brought to this area anytime through the
month of November. This help will be greatly appreciated.
For further information contact Lee Schwade at the Denver
Botanic Gardens — 297-2547, Ext. 5.

Be sure to read The American Horticulturist, Summer
1976. In it you will find an article on the Colorado
columbine by the Director of the Gardens, Dr. William G.
Gambill, Jr. It is beautifully illustrated by Loraine Yeatts’
picture of flowers from Yankee Boy Basin.

PROTECTION OF WILDFLOWERS

The breath of flowers is far sweeter
in the air than in the hand.

Francis Bacon (1561-1626)
English philosopher

Our wildflowers are appealing,

A joy to one who seeks;

And those attuned to nature
Their silent beauty speaks.

Let no one still their voices in
Some withering bouquet;

As such they have no fragrance
Nor beauty to display.

For those who may not understand
The pleasure that is ours;

We hope they too will find it
Expressed in living flowers.

Carl W. Tempel, M.D.

(Member of the Denver Botanic Gardens)

* * * * * *

To Organizations that use the Facilities of the Denver
Botanic Gardens.

Are you planning any special events that are open to the
public? If so, remember we are glad to help publicize such
events in the Newsletter. Please send copy to 909 York
Street by the tenth of the month prior to the event. Mark
the envelope “Newsletter”.

******

BOTANY CLUB
Friday, October 15
7:30 p.m., Classroom C

Since fresh plants are not now available, this meeting
starts the season for special slide shows. Dr. Richard B.
Schwendinger, who was the bioengineering supervisor for
Alyeska Pipeline Service Co., will show pictures taken while
he worked in Alaska.

Since the Denver Botanic Gardens is working on details
for an Alaskan trip next year this should be of special
interest. All welcome.

AND

The Rocky Mountain Bromeliad Society will meet on
Monday, October 18th at 7:30 p.m. in Classroom B. Dr.
Richard Schwendinger will lead a discussion and demonstra¬
tion of raising bromeliads from seed. All interested persons
are invited to attend.

Additional information can be obtained from Larry
Mason, 233-0577.

Join us for the free film, “Wonders of the Wilderness,”
on October 9 at 1:30 p.m. Classroom C. This film was
produced by Colorado State University in cooperation with
the U.S. Forest Service. It takes viewers on a pack trip with
the American Forestry Association trail riders into the
Maroon Bells — Snowmass Wilderness area of the White
River National Forest. Free.

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LIBRARY ADDS NEW ORCHID BOOKS

The Helen Fowler Library has attempted to acquire
volumes on Orchidaceae to meet the needs of the staff, the
members of the Denver Orchid Society and the public. The
growing orchid collection at DBG needs to be sustained by
good sources to identify specimens and to indicate cultural
needs.

Besides 55 books on orchid culture, the Library has the
following recent accessions on local flora:

Europe:

Hermjakob, Gerd. Orchids of Greece and Cyprus: 1. the
Genus Ophrys. Kiffissia, Greece, The Goulandris Natural
History Museum, 1974.

North America, North of Mexico:

Luer, Carlyle A. The Native Orchids of the United States
and Canada Excluding Florida. New York, New York
Botanical Garden, 1975.

Sheviak, Charles J. An Introduction to the Ecology of the
Illinois Orchidaceae. Springfield, Illinois State Museum,
1974.

Luer, Carlyle A. The Native Orchids of Florida. New York,
New York Botanical Garden, 1972.

Bingham, Marjorie Tellefsen. Orchids of Michigan. Bloom¬
field Hills, Mich., Cranbrook Institute of Science, 1939.
Szczawinski, Adam F. Orchids of British Columbia. Victoria,
B.C., A. Sutton, 1970.

Central America:

Dressier, Robert L. The Genus Encyclia in Mexico. Mexico,
Asociacion Mexicana de Orquideologea, 1974.

Halcrow, Magnus. Orchids of Belize. Belize, British
Honduras, Govt. Printer, s. a.

Hamer, Fritz. Tas Orquideas de El Salvador. San Salvador,
Direccion de Publicationes, Ministerio de Educacion,
1974.

Lapiner, Jean M. de. Orquideas Michoacanas. Mexico, s. a.
Williams, Louis Otho. The Orchidaceae of Mexico.
Tegucigalpa, Honduras, Escuela Agricola Panamericana,
1965.

Wright, N. Pelham. Orquideas de Mexico. Mexico, D.F.,
Fournier, 1958.

South America:

Dunsterville, G. C. K. Venezuelan Orchids Illustrated.
London, A. Deutsch, 1959-

Hoehne, Frederico Carlos. Iconografia de Orchidaceas do
Brasil , Generos e Principals E species em texto e em
Ptanchas; Resume e Complemento da Monografia das
Orchidaceas na “ Flora Brasilica. ” Sao Paulo, Secretaria
de Agricultura, 1949.

Schultes, Richard Evans. Native Orchids of Trinidad and
Tobago. New York, Pergamon Press, 1960.

Schweinfurth, Charles. Orchids of Peru. Chicago, Chicago
Natural History Museum, 1958-61.

Africa:

Morris, Brain. The Epiphytic Orchids of Malawi. Blantyre,
Malawi, The Society of Malawi, 1970.

Piers, Frank. Orchids of East Africa. Lehre, Cramer, 1968.

Stewart, Joyce. Orchids of Tropical Africa. South Brushwick,
A. S. Bames, 1970.

Pacific:

Lin, Tsan-Pias. Native Orchids of Taiwan. Taipei, China,
Distributed by J. F. Hsiung, 1975.

Su, Horng-Jye. Native Orchids of Taiwan. Taipei, Harvest
Farm Magazine, 1975.

Atlantic Islands:

Garay, Leslie A. Orchidaceae. Arnold Arboretum, Harvard
University, 1 974.

Recent monographs on orchid studies new to the collection

are:

Ebel, Friedrich. The Strange and the Beautiful World of
Orchids. New York, Van Nostrand Rienhold Co., 1972.

Fowlie, Jack A. The Genus Lycaste: Its Speciation, Distri¬
bution, Literature, and Cultivation - a Monographic
Revision. Pomona, Calif., Azul Quinta Press, 1970.

Simon, Hilda. The Private Lives of Orchids. Philadelphia,
Lippincott, 1975.

Withner, Carl Leslie. The Orchids: Scientific Studies. New
York, Wiley, 1974.

Green Thumb Newsletter is published monthly by Denver Botanic Gardens,
Inc., 909 York Street, Denver, Colorado 80206. The Newsletter is included as a
benefit of membership in the Denver Botanic Gardens, regular membership dues
being $ 1 0.00 a year. Items for publication are welcome. The deadline for copy to
the editor is 2:00 p.m. on the 10th of each month preceding publication.

Editor — Margaret Sikes — 297-2547

DENVER
BOTANIC
GARDENS, INC.

Green Thumb Newsletter

Copyright 1976

No. 76-11 . NOVEMBER 1976 297-2547

GARDENING TIPS FOR NOVEMBER

NATURE'S PREPACKAGED
FLOWERS

Forcing bulbs indoors can not only be fun and provide a
colorful and unique display during the cold winter months,
but can also be accomplished relatively easy. It is now
possible to purchase bulbs already conditioned for forcing
along with complete instructions that will bring them into
satisfactory bloom. Unfortunately, these are usually
restricted to indoor types that are not hardy bulbs. An
example is the paper white narcissus. For those that want to
be more adventuresome, you may wish to use some of the
common outdoor varieties including tulips and many
varieties of daffodils. You can follow certain procedures that
will eventually give you colorful displays throughout the
winter.

Tulips, hyacinths and narcissi bulbs have -been referred
to as nature’s prepackaged flowers. In a sense, this is true in
that each bulb contains within it a perfectly-formed flower,
providing the bulb is of the proper size, and all the necessary
nutrients; requiring only the proper environment and suffi¬
cient time for it to explode into bloom.

Most of the bulbs that are purchased for outdoor use
need further conditioning, however, before blossoming is
possible. In other words, a bulb purchased from the store
now, unless it has been pre-conditioned, would not force
satisfactorily into a flowering plant. Usually it will simply
rot or produce foliage and nothing else. This is because most
spring flowering bulbs, with the exception of some narcissi,
do not really have all of the flower parts fully developed
when they are harvested and sold. To achieve further
development, somewhat exacting stages at varied tempera¬
tures are required. Commercial growers follow all these
different stages in order to achieve the types of potted bulbs
you can buy at Christmastime or most any other time during
the winter months. We’ll try to simplify the procedure for
those who wish to undertake forcing outdoor bulbs inside
their homes.

Tulips are probably the most challenging because they
have to have the most exacting temperature requirements.
Basically, all bulbs should be stored until planting time at a
temperature around sixty to sixty-five degrees. At planting
time the temperatures are gradually reduced over a period of
several weeks until they are kept at approximately forty-one
degrees. This is close to the temperatures of most lower
shelves in a refrigerator. In fact, if you have a spare
refrigerator, you might consider it for this purpose. A cold
period is needed during which time rooting takes place; six
to eight weeks for hyacinths and narcissi, and up to fifteen
weeks for tulips.

Following the cold treatment, the flower buds within
should be fully matured and are ready for forcing. If planted
at various times on a staggered schedule it is possible to then
bring them out of storage to come into blossom at any
desired time during the winter months. Bringing them out of

(Continued next page)

ANNUAL PRE- HOLIDAY
GIFT SALE-NOV. 19 AND 20

Heavenly -scented fragrance gifts, handcrafted yuletide
treasures, zesty herb vinegars and herb salt, delightful
botanical harvests — these ARE Christmas at Denver Botanic
Gardens Gift Shop’s annual pre-holiday sale scheduled
November 19 and 20 in Boettcher Memorial Center, 1005
York Street. Sponsored by Associates the sale will be held
from 10 a.m. to 4:30 p.m. both Friday and Saturday.

Fragrance Gifts. Lemon is the latest scent in potpourri
offered in perky sachets, in elegant glass boxes lined with
forever flowers, in domed jars or in china containers. Pepper¬
mint perfumes tranquility pillows. Other potpourri fragrances
are lilac, lily-of-the-valley, sandalwood, lavender, carnation
and rose. Rose potpourri is also offered in bulk for personal¬
ized packaging.

For those who mix their own potpourri, hard-to-find
ingredients include a variety of oils and fixatives such as
orris root, patchouli, vetiver, tonka beans as well as oils in
musk, ambergris and musk amberette. Fruit or floral scented
glycerine soaps and exotic room scents will be available.

Popular, too, at Fragrance Center are vanilla beans,
cinnamon sticks, herb salt, plus frankincense and myrrh.

Yuletide Treasures. Par¬
tridges perch in decorative sugar
scoops or dippers, bath soaps
are ribboned and embellished
with birds and flowers, cone
wreaths big to small have been
created in special workshops.

Ornamentally, exotic shells
dangle within circlets of gold —
these graced last year’s
Christmas tree and will be
offered. Here, too, are hand-studded balls of stars-over-Persia.

Herb Vinegars have been brewed from a generations-old
recipe by members of the Guild.- Last year 1800 bottles of
regular and tarragon vinegars were sold to further develop¬
ment of the nationally-known herb garden at Denver Botanic
Gardens.

Cones, Pods and Seeds have
been gathered for those who
wish to make their own holiday
arrangements. Bells of Ireland,
golden yarrow, stems of teasel
and money plant as well as
contrived flowers from Osage
oranges have been prepared by
members of Around the
Seasons Club — their annual
effort at this event.

Gifts for Children. Whimsical figurines have been
fashioned from nuts and seeds. Old-fashioned calico finger
puppets, cuddly velour animals (bean bag variety), antique¬
like dolls with bisque heads and jointed limbs of wood are a
few of many suggestions. Little Red Ridinghood displays a
(Continued back page)

storage requires some temperature control also. Normally the
bulbs are removed from storage and placed in a dark,
relatively cool location; preferably sixty-five degrees as might
be found in many home basements.

Soon thereafter, it will be observed that shoots appear
and when they have reached one to one and one-half inches
in length, the plants should be brought out into a light room
but away from direct sunlight. They will develop rapidly at
normal room temperatures, flowering anywhere from four to
eight weeks after removal from storage, depending on the
type of bulb.

Bulbs should be forced in the containers you intend to
grow them because they will not tolerate being moved once
rooting has taken place. Most any container is suitable and it
is usually preferable to use soil but well-drained material
such as gravel or a mixture of gravel and peat can also be
used. Some prefer to use a decorative apoxy-coated gravel
such as is used in aquariums, selecting a color that will fit
the decor of the container and the home as well.

Since the bulbs contain all the nutrients they need, you
need not worry about adding any fertilizer. The only
concern is to avoid drowning the bulbs by submerging them
in too much water. The bulbs should be so placed in the
planting medium that they are partly exposed above the
surface and the water level should be maintained so that
only the base of the bulb is in contact with free water.

After the bulbs have finished blooming, it generally does
not pay to try to grow them on and save them. It is then
that they need nutrition and when growing in a gravel
culture, this can become a difficult chore. If you are growing
them in soil rather than in gravel or a mixture, they can be
salvaged but again, it would be difficult since light condi¬
tions in most homes would not permit adequate food
development by the leaves with which to grow new bulbs.

Houseplant Care

The winter months generally bring on some illnesses in
houseplants because of reduced light intensity but probably
more so due to very low humidity in most homes. The most
common complaint is that the lower leaves of the plant
begin to dry up, develop brown leaves or they turn yellow

and fall off. While several things can cause this, the most
common cause for this condition is continuing to frequently
water the plant, as you might have done in the summer,
when the plant is now attempting to slow down its own
growth rate. This usually results in getting the soil wetter
than normal and providing more water than the plant can
use. This leads to root rot and corresponding foliage drop.

The secret to successful houseplants during the winter
months is gradually reducing the frequency of watering but
when you do water, water thoroughly so that it runs
completely through the container and any surplus water
drained off from the catch basin below. Another method,
that will also increase humidity a little bit, is to fill the
catch basin with coarse sand, resting the pot on the surface
of the sand and the remaining water in the catch basin will
not be taken back up into the soil. When this happens, a
boggy root system develops along with an accumulation of
soluble salts. This is the white stuff you see around the rim
of the pot and for that matter, sometimes on the soil
surface.

Another important part of keeping houseplants healthy
in the winter months is making sure that they are away from
drafts such as doors that lead to the outside. Neither should
they be placed on window sills that conduct cold. If you
happen to have, as I do, aluminum windows and terrazzo
window sills, you have the worst combination for growing
houseplants. The plants should be moved away from these
places, being careful that they do not end up on top of the
TV set nor near heating outlets. This is particularly impor¬
tant if you have forced air heat because this type of unit
causes sudden changes in the air temperature in the vicinity
of the plant; first being very warm then, since most furnaces
of this type have fans that continue to run after the heat
source has been shut off, cold air begins to circulate.

Household insects may also be a problem. These can
include spider mites, mealy bugs and white .flies. If you have
just recently purchased plants from a greenhouse or garden
center or, for that matter your local grocer, beware. Quite
often these are sources of new infestations. Just as tropical
fish fanciers will routinely treat newly introduced fish for
possible disease that might get into the tank, a good
houseplant grower will routinely treat houseplants that have
been newly introduced for insect problems. Examine them
carefully but even close examination may not reveal the tiny
eggs of spider mites which will soon hatch in your warm
home and before you know it, the damage appears on the
foliage. Use only an approved insect control material
designed for indoor use. Many of these come in aerosol
sprays. Pay close heed that you hold the container from
twelve to eighteen inches away from the foliage. The
propellants used in the aerosols are at subfreezing tempera¬
tures near the nozzle and can do considerable damage to
houseplants if held too close to them. Use sprays only in
adequately well-ventilated areas and away from food or food
serving areas. Even those sprays approved for indoor use can
be very toxic so follow carefully all directions appearing on
the label.

Happy Gardening and Happy Thanksgiving!

Dr. J. R. Feucht

“Habits and customs differ but all people have the love
of flowers in common.” This Chinese proverb seems
particularly appropriate for the Lobby Court display this
month. The yellow and orange chrysanthemums
predominated earlier, but now the shades are those of purple
and red. Hard to decide which is lovelier!

mj

NOVEMBER

2) 7:00 a.m.

7:00 p.m.

2)*

10:00 a.m.

2)*

10:00 a.m.

2)

7:30 p.m.

3)*

10:00 a.m.

3)*

1:30 p.m.

3)

7:30 p.m.

4)

7:00 p.m.

4)*

7:45 p.m.

5)

1 1:00 a.m.

6)*

8:30 a.m.

6)

9:30 a.m.

8)

7:30 p.m.

8)

7:30 p.m.

9)

9:30 a.m.

9)*

10:00 a.m.

9)*

4:00 p.m.

9)*

7:30 p.m.

9)

7:30 p.m.

10)*

9: 15 a.m.

10)*

7:30 p.m.

10)

7:30 p.m.

11)

9:00 a.m.

12)

9:00 a.m.

12)*

9:45 a.m.

12)

7:30 p.m.

13)

9:00 a.m.

13)

1:30 p.m.

15)*

9:30 a.m.

15)

7:30 p.m.

16)*

10:00 a.m.

16)

12:30 p.m.

16)

7:30 p.m.

16)

7:30 p.m.

DENVER BOTANIC GARDENS

Education Building

Horticulture Hall

NOVEMBER, 1976

General Election

Education Building — Lecture Room “B”
Education Building — Herbarium
Education Building — Lecture Room “A”
Education Building — Lecture Room “B”
Education Building — Lecture Room “C”
Education Building — Lecture Room “A”
Education Building — Lecture Room “C”
Education Building — Horticulture Hall
Botanic Gardens House — Main-Dining-Kitchen
Education Building — Lecture Room “B”
Botanic Gardens House — Main Room

Intermediate & Advanced Bonsai - Mrs. Mary Neil
Herbarium Committee Meeting
Colorado Council of Trout Unlimited
“Unusual Container Plants” - Mr. Andrew Pierce
Tropical Plants of the Conservatory - Mrs. P. Hayward
Audubon Society Meeting (Conservation Committee)
Colorado Open Space Council
Denver Orchid Society Meeting
Civic Garden Club

Denver Public School Teachers Class - Dr. John Brennan
Gloxinia Gesneriad Growers

Education Building — Horticulture Hall
Education Building — Lecture Room “A”
Education Building — Lecture Room “A”
Education Building — Lecture Room “B”
Botanic Gardens House — Dining Room
Education Building — Horticulture Hall
Education Building — Lecture Room “B”
Botanic Gardens House — Main-Dining-Kitchen
Education Building — Lecture Room “A”
Education Building — Lecture Room “B”
Education Building — Horticulture Hall
Education Building — Lecture Room “C”
Education Building — Horticulture Hall
Botanic Gardens House — Main-Dining-Kitchen
Education Building — Horticulture Hall
Education Building — Lecture Room “C”

Colorado Mycological Society Meeting
Denver Sierra Club (Wildlife Committee)

Civic Garden Club - Division “C”

Intermediate & Advanced Bonsai - Mrs. Mary Neil

Executive Committee Meeting

E.C.C. Nature Study Unit

Sierra Club (Energy Committee Meeting)

D.B.G. Guild Meeting

Landscape Industry Council

Denver Commission on Community Relations

Keep Colorado Beautiful

Keep Colorado Beautiful

Ikebana International

Denver Dahlia Society

Keep Colorado Beautiful

Film: “Think Like a Mountain”

Education Building — Lecture Room “B”
Education Building — Lecture Room “B”
Education Building - Lecture Room “B”
Botanic Gardens House — Main-Dining-Kitchen
Education Building — Horticulture Hall
Education Building — Lecture Room “B”

Central District of President’s Council
Rocky Mountain Bromeliad Society
President’s Council of Federated Garden Clubs
Rocky Mountain African Violet Council
Sierra Club - General Meeting
Denver Bonsai Club Meeting

CALENDAR OF EVENTS FOR NOVEMBER (Continued)

18)*

10:00 a.m.

Botanic Gardens House — Main Room

Around the Seasons Meeting

18)

7:30 p.m.

Education Building - Lecture Room “A”

Colorado Open Space Council

18)

7:30 p.m.

Education Building — Lecture Room “C”

Organic Garden Club Meeting

19)

10:00 a.m.

Education Building — Horticulture Hall

GIFT SHOP CHRISTMAS SALE

OPEN TO PUBLIC: 10:00 a.m. - 4:30 pan.

19)*

7:30 p.m.

Education Building — Lecture Room “B”

Colorado Bonsai Club Meeting

19)

7:30 p.m.

Education Building — Lecture Room “C”

Denver Botany Club Meeting

20)

9:30 a.m.

Education Building — Lecture Room “B”

Hi -Country Judges Workshop

20)

10:00 a.m.

Education Building — Horticulture Hall

GIFT SHOP CHRISTMAS SALE

OPEN TO PUBLIC: 10:00 a.m. - 4:30 pjn.

22)

9:30 a.m.

Botanic Gardens House — Main Room

Ultra Violet Club

22)

7:30 p.m.

Education Building — Lecture Room “B”

Sierra Club (Wilderness Workshop)

23)*

4:00 pjn.

Botanic Gardens House — Conference Room

Board of Trustees Meeting

23)

7:30 p.m.

Education Building — Lecture Room “C”

Gladiolus Society Meeting

25)

“HAPPY THANKSGIVING DAY”

29)*

7:30 p.m.

Education Building — Lecture Room “A”

Nature Conservancy Meeting

DECEMBER

1) 7:30 pjn.

Education Building - Lecture Room “A”

Audubon Society Meeting

2)

7:00 p.m.

Education Building — Lecture Room “C”

Colorado Open Space Council

2)*

7:45 p.m.

Education Building — Horticulture Hall

Denver Orchid Society

3)

1 1:00 a.m.

Botanic Gardens House — Main-Dining-Kitchen

Civic Garden Club

4)

9:00 a.m.

Education Building — Horticulture Hall

Denver Audubon Society Art Exhibit

OPEN TO PUBLIC: (December 4th through 12th)

4)

1:00 p.m.

Education Building — Lecture Room “A”

African Violet Club

*Members or Enrollees Only

High Altitude Research -

A CSU-Pitkin County Project

The Department of Horticulture at Colorado State
University, in cooperation with Pitkin County, centered in
Aspen, has initiated a long-term study of horticultural plants
and their performance at high elevations.

Using a grant by the county, and land donated by Mr.
John Stem of Aspen, Colorado, the plans call for the
ultimate development of a research and education center
located near Snowmass Village.

For the past two summers, researchers have planted
experimental plots of ground covers, trees, shrubs, legumes
and grasses at numerous locations near Aspen and Snowmass.
Included are soil stabilization studies on steep road cuts and
shale outcrops. Also included in the research are evaluations
of vegetables and fruits that could be utilized for local home
gardeners and on a production scale for local consumption.

In cooperation with Aspen Ski Corporation, four
experimental sites have been planted at Snowmass Ski
Corporation and four experimental sites have been planted at
Snowmass Ski Area. These sites are also being fully
instrumented to monitor climatic conditions including air
and soil temperatures, solar radiation, snow depth, rainfall,
and wind velocity.

Experimental plots installed so far, range in elevation
from 7,800’ to 10,500’ and on slopes up to 35 degrees.

Cooperating investigators on the project are: Dr. Jackie
D. Butler, Extension Professor, Turfgrass; Dr. James R.
Feucht, Extension Professor, Landscape Horticulture; Dr.
Frank D. Moore, Associate Professor, Vegetable Crops, and
Dr. Bert T. Swanson, Assistant Professor, Landscape
Horticulture, Colorado State University.

Botany Club - Nov. 19 - 7:30 Classroom "C”

“Kissin’ Cousins of the East” presented by Albert Daraghy.
A slide show of flowers of the eastern United States. Free
and Open to the Public.

HELP PLEASE!

Don’t forget we are having a book sale in May. Your
used books would be most welcome. Please call 297-2547,
Ext. 24 for more information.

Orchid Show 1976

For those who attended this year’s show, a very wide
range of genera was on display in the Horticultural Hall and
the whole theme Art in Orchids was beautifully executed.
For those who missed the opportunity I can only suggest
that when next year’s dates are published you make a note
to attend. The Gardens participated with a table display that
was awarded first prize for special exhibit and one of the
staff, Larry Latta, was recipient of a best orchid in the show
award with his Stanhopea oculata.

Garden and display participation by the D.B.G. helps all
concerned even if it’s on a non-competitive basis.
Unfortunately, even though we have fairly extensive
collections back in the greenhouses, we lack areas for public
viewing and such shows as the Denver Orchid Society’s give
us the opportunity to show off some of our plants.

SPECIAL GIFT

Our thanks to Norman Cohn for his handsome donation
of forty orchids to our collection. These were grown in his
fifteenth floor greenhouse and include several clones awarded
by the American Orchid Society and the Royal Horticultural
Society. Visitors will be able to admire some of these plants
in the orchid case or on the pedestals in the Lobby or on
display in the Conservatory. Not only plants were included,
for the Library also received lovely photographs and a very
special book, The Complete Edition of Orchids of Australia
by W. H. Nicholls. This is number 24 of 150 copies and may
be viewed in the Waring Rare Book Room.

INVENTORY REPORT

Mr. Pierce reports that the two new greenhouses contain
1700 species, varieties and cultivars. This count includes
major groupings of palms, insectivorous plants, ferns, cacti
and other succulents. The approximately 340 orchids are not
included in this inventory nor are the 620 species, varieties
and cultivars in the Conservatory.

NEW BOARD MEMBER

Mr. John C. Mitchell, President of the Board of
Trustees, has announced the election of William J. Lunsford
to the Board.

Donations have been gratefully received in memory of:

Helen C. Bosworth
Marmaduke B. Holt, Jr.

Cora B. Mayo

FREE FILM

“Think Like a Mountain” is a new Forest Service film
dealing with rare and endangered species of wildlife. This is
scheduled to be shown on November 13th at 1:30 PM in
Classroom C.

DID YOU KNOW?

The U.S. Postal Service charges 25<t for every Newsletter
that isn’t delivered to a subscriber and 53<t for every Green
Thumb magazine that is returned.

Won’t you help us get our publications to you without
delay and without extra charge to the Gardens? Please be
sure to let us know in advance of a change of address.
Thank you.

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CHRISTMAS SALE (Continued)

triple personality: simply by folding her felt skirt she
becomes Grandma, another fold and she’s the mean old
wolf. Perennially popular is the complete line of Beatrix
Potter books, puzzles and figurines.

Books to Cherish. More than 600 titles represent the
newest or best volumes on gardening, ecology, wild flower
identification. They range in scope from coloring books to
college texts. Publications of Denver Botanic Gardens include
What Tree Is This?, a simple key for tree identification, and
Meet the Natives, an amateur’s guide to wild flowers. Wild
Flower Name Tales, Anderson; Rocky Mountain Dye Plants,
Bliss; and the new edition of Rocky Mountain Flora, Weber;
Kelly’s latest works are A Way to Beauty and Trees for the
Rocky Mountains. Herbs are considered in 50 different titles
including the classic Herbal by Joseph Wood Krutch, offered
in paperback at $ 10.

Gourmet Pleasers. Herb plants growing in pots or
planters will be available once more as well as ever-popular
herb salt, prepared by Tussie Mussie Mesdames. Birds
decorate French dessert plates; violets or roses are featured
on Spode cups and saucers. Placemats and linen towels in
flower or bird motif and tile trivets have been chosen for
sale. In wood are spoon racks, coffee grinders, salt and
pepper mills, mixing spoon trees and spatulas. Butter molds
and large deep molds will be offered in pottery, and of
course, casseroles in ceramics.

Jewelry includes neckpieces, bracelets and earrings
created by volunteers from unusual seeds, beads and clay
medallions. Juniper berry necklaces are made by Navajos
living near Bluff, Utah and other necklaces of semi-precious
stones have been made in Brazil.

Gifts from Near and Far. Metallic aspen leaves and
branches, some adorn fine wood; Laser-engraved walnut desk
accessories with nature designs; Norwegian crystal in paper
weights, ash trays and vases; Kashmir boxes lacquered in
vivid floral and animal motifs; goldtone powder room
accessories (comb and brush sets, jewel boxes, wastebaskets);

carved stone figurines from Russia; copperwashed tinware;
olive wood creches from Israel and Hummel figurines by
Goebel; pristine madonnas in ceramics, simistone, glass or
pottery.

Nostalgia Teasers. Music boxes, wind chimes, mobiles,
thimbles and many collector’s items.

Certificates from the Gift Shop and, of course, member¬
ships in Denver Botanic Gardens are always welcome gifts.

Gifts, whether handmade or selected, all have a hint of
nature. Naturally, all proceeds benefit Denver Botanic
Gardens.

GARDENS TO HOST WILDLIFE ART SHOW

Original works and prints of locally prominent and
nationally renowned artists will be featured at the Wildlife
Art Exhibit and Sale to be held December 4th through 12th
at the Denver Botanic Gardens, Horticulture Hall. The event
is sponsored by the Denver Audubon Society, and proceeds
from the sale will benefit such Audubon projects as the
study of habitat along Cherry Creek drainage, field studies of
migrating and nesting birds at Barr Lake State Park, and the
building of a public observation blind at Barr Lake.

For further information regarding the Wildlife Art
Exhibit and Sale, call the Denver Audubon Society,
893-5883.

Gladiolus Slides Needed

Did anyone take colored slides of the gladiolus garden
this summer? If so, and you’d care to share, we would
appreciate hearing from you.

ROCK WANTED -

Does anyone have a floating pumice rock? The turtles in
our conservatory would really appreciate such a donation.
Thank you.

Green Thumb Newsletter is published monthly by Denver Botanic Gardens,
Inc., 909 York Street, Denver, Colorado 80206. The Newsletter is included as a
benefit of membership in the Denver Botanic Gardens, regular membership dues
being $10.00 a year. Items for publication are welcome. The deadline for copy to
the editor is 2:00 p.m. on the 10th of each month preceding publication.

Editor — Margaret Sikes — 297-2547

DENVER
BOTANIC
GARDENS, INC.

Green Thumb Newsletter

Copyright 1976

No. 76-12 DECEMBER 1976 297-2547

GARDENING TIPS FOR DECEMBER

Protect Against
Winter Burn

December always seems to be a difficult month to talk
about gardening but there is one little chore that may need
to be done, depending on the weather conditions, and that is
to deep water your trees and shrubs, particularly if the
month turns out to be dry as it has been in the past two
Decembers. Even though the surface of the soil may be
moistened by occasional snows, it is important to put the
water down deeply because moisture where the roots are
may be completely depleted. The best way to do this is to
use a hose-attached soil needle such as the Ross Root
Feeder. It is not necessary to leave it in the ground for long
periods of time but it should be moved short distances
leaving it in each spot perhaps no more than one-half
minute. In this way you will distribute the water more
evenly but not tend to overwater the plant.

Some garden centers are advertising the use of anti¬
desiccants to reduce winter drying in evergreens. Materials
such as “Wiltpruf’ and “Vapoguard” are frequently used in
the nursery trade to reduce water loss during transplanting
Unfortunately, these materials are not as successful in the
arid climate of Colorado as they are in the eastern and
mid-western states. There is also a danger in the use of some
of these when applied during cold weather because they may
last too long, forming a film on the leaf surface and blocking
the breathing pores (stomates) and not only cutting down
water loss but reducing respiration and photosynthetic
activity as well. This can lead to injury to the plant caused
by the suffocation not only of the tops, but can reduce food
transport to the roots resulting in starvation. If you have
evergreens that tend to wind bum during the winter months,
it is probably better to protect them with loose wraps of
burlap or by erecting some kind of wind barrier, than it is to
use the chemical anti-desiccants.

If you have tried late fall transplanting and just recently
moved some trees and shrubs, it is highly recommended that
you mulch the surface of the ground in order to prevent a
deep freezing of the soil. This will give the roots a chance to
establish. Otherwise, the plant may dry out because it does
not have sufficient roots to compete with water loss. Here
again, the chemical desiccants may be helpful if used
properly but erecting a physical wind barrier will usually
serve more effectively.

Cut vs. Live Christmas Trees

Each year this column has discussed the virtues of
buying a cut Christmas tree as opposed to the purchase of a
live tree. Live Christmas trees have seemed to become quite
popular in this “ecological age” but the reader should be
reminded that planting a live tree following the Christmas
season is often a very difficult task and may result in not
saving a tree, but rather wasting a natural resource. A lot
depends on the weather conditions and how much
(Continued next page)

“Elf Owl” — Peter Parnall

©Greenwich Workshop

AUDUBON SHOW

A Wildlife Art Exhibit and Sale, sponsored by the
Denver Audubon Society, will be held in Horticulture Hall
from December 4th through the 12th.

The show, open to the public during Garden hours (9 to
4:45 daily), will feature original paintings by Donald L.
Malick, one of the leading bird artists today. Mr. Malick has
painted several dioramas at the Denver Museum of Natural
History. Other artists include Don Eckelberry, Bruce Dines,
Eldridge Hardy, and Tucker Smith. The prints feature some¬
thing for every wildlife interest: duck hunters will enjoy the
faultless detail of the “Green-winged Teal” by Jo Polseno;
zoo lovers will be attracted by John Schoenherr’s large
mammals; Peter Parnall’s prints captivate the whimsical
nature of wildlife; and the traditional wildlife enthusiast will
enjoy the antique prints of John James Audubon.

For further information regarding the Wildlife Art
Exhibit and Sale, call the Denver Audubon Society,
893-5883.

The Helen Fowler Library, Denver Botanic Gardens, is
now part of the Central Colorado Library System and
as such, will enjoy the services of the courier. Books
borrowed from the Helen Fowler Library may be
returned to any of the participating libraries, e.g. all
the public libraries in the Denver metropolitan area.
Books from these libraries may be returned to the
Helen Fowler Library where the courier will pick them
up and route them to their proper home.

“New Books for Old” is a motto of the Library, if
you’ll help! We sell second hand books at the Sale in May
and then use the money to buy new books for the collec¬
tion. Therefore, we need lots of donations. Please call
297-2547 ext. 24 for more information.

preparation you do prior to the purchase of the tree. If you
are contemplating using a live tree, prepare the soil now;
digging the planting hole in a permanent location. Place the
soil removed in an area where it will not be frozen. Be sure
to cover the hole so that someone cannot accidentally fall
into it.

A live tree should not be left in the home for more than
about three days, otherwise it may start to break dormancy
and will not be able to cope with the sudden change to cold
temperatures when taken outside again. If the weather is bad
following Christmas, take the tree to a cold location such as
your garage, making sure to keep the soil slightly moist until
there is a clear day to plant it outside. In the process of
planting, it is a good idea to thoroughly mix in some coarse
peat moss to improve aeration and drainage and following
planting, you should cover the surface with a deep mulch
such as wood chips or similar materials that will insulate the
soil from a hard frost. Avoid overwatering the plant, keeping
in mind that in the winter months soils do not dry out
rapidly once they have become moistened because of the
lower temperatures.

For those purchasing a cut tree, you will get much more
satisfaction if you select from Christmas tree lots that have
the fresh cut and if possible, native species. Many of the
imported trees are cut as much as two months ahead of
schedule and may be fairly dry. One way to check them is
to stand them up and tap them firmly on the ground and
watch for needle drop. Be wary also of those trees that have
been sprayed with colorant because this often masks the
off-green color of trees that are getting too dry. Dry trees
are not only a mess in the home but a decided fire hazard.
As to tree types, the best are the Scotch Pine, Douglas-fir
and true fir. Most spruce dry quickly and thus drop needles
readily. The Douglas-fir and true fir will have a soft feel to
the needles. Spruce will have sharp needles which are square
in cross section. Douglas-fir and true fir have flat needles.

After you have purchased a cut tree it is best to saw off
a portion of the base (six inches is enough) to expose a fresh
cut and then plunge the base in a bucket of water until it is
time to bring it indoors. This will help the tree to maintain
freshness, providing you keep the tree in a shaded and cool
location. An unheated garage or the north side of the
building would be suitable. It is also a good idea to use a
Christmas tree stand that has a container for holding water.

Houseplant Care

This column has already mentioned the ills that house-
plants incur during the winter months, mostly as the result
of lower humidity when the furnace is turned on. It is a
good idea to keep your house plants on the dry side in order
to keep them slowed down in growth. This will reduce the
demands of the plant and it will be better able to cope with
lower humidity and lower light conditions. Poinsettias are a
popular plant this time of year and they too, should be kept
pretty much on the dry side. Poinsettias are also very
sensitive to cold drafts of air or even sudden changes in
warm temperatures. It is best to keep them away from direct
sunlight and from heat outlets as well as from the doorways.

I hope you’ve all had a pleasant gardening year and
Merry Christmas!

Dr. J. R. Feucht

WINTER LIST OF CLASSES

By now all members should have received the Winter
List of Classes. It is hoped that everyone will find something
of interest to himself and will be free to participate at the
time as listed.

Diane Lewis of the Canaan Center for Creativity will
teach several more classes for children than were offered
before. In fact her classes in September were such a success
that children asked if they couldn’t come back the next
Saturday! Art Workshops for Children on December 4 will
help the students create flowers from play dough and natural
materials — pine cones, dried plant materials and bits of
wood. The hours are 9-10 a.m. or 1:30-2:30 p.m. for grades
1 to 3 and for the older grades, 10:15-12:15 or 2:45-4:45
p.m. Limit 10 each session. Fee $1.25

Last year the Applewood Seed Company Tour filled up
promptly so do not delay in placing your name on the list.
December 9 is the date. Meet the group at 909 York at 1:30
p.m. of if you prefer, at 2 p.m. at 833 Parfet. (Turn north
off 6th Avenue at Simms; go one block to 8th and turn east
to Parfet. There is a large complex on the northwest comer
— follow the Applewood Seed Company sign to the west
side of the building.) Limit 10. Free.

Guiding is Fun will be an excellent preview for the next
guide class, Tropical Plants of the Conservatory, which will
start in January. Come at 9:30 or 10:30 a.m. on December
6th or 8th and join a regularly scheduled tour of the
Conservatory. This is your chance to see what a guide does.
Limit 4 each time. Free.

A gift from Clifford Schaffer will really be a great help
to the guides. They had wanted a tape recorder for their
classes and tours and Cliff provided one. Thanks to him
Santa came a little early this year!

Several classes starting in January will be of interest also.

“Did you know that in the early exploratory years of
the garden revolution in England, hermitages were estab¬
lished in some estate gardens. These were caves or squalid
huts wherein resided hermits hired specifically to serve as
wild or poetic fixtures. They were commonly instructed to
let hair, fingernails, and beards grow, to wear robes, and in
general to appear romantically uncouth. Since such persons
were hard to keep employed pay and benefits were liberal.
Even so, few flesh-and-blood hermits measured up to the
rigors of the job. They were eventually replaced by stuffed
hermits, and so, perhaps, began a new tradition of lawn
ornamentation, that has given us pink flamingos, reflection
globes, wishing wells, and a multitude of cheerful dwarves.”
(From A History of Garden Design by Derek Clifford.
Reprinted by permission of Praeger Publishers, Inc.)

It is doubtful that Mr. Rollinger and Mr. Watson will
recommend such attractions in their Landscape Horticulture
class but they will teach about design principles and plant
materials. The class is from January 6-February 24,
7:15-9:45 p.m. in Classroom C. The cost is $15.00.

In Indoor Light Gardening taught by two members of
the staff of the Denver Botanic Gardens, many areas will be
covered including Light Basics and Equipment; also two
sessions will focus on General Plants, flowering and foliage
and Specific Plants like orchids, gesneriads, and bromeliads.
The class will be taught on Wednesday nights from January
12 to February 9 from 7-8 p.m., Classroom A. The fee is
$7.50.

SPECIAL FLASH

Word has just been received that Avalonne Kosanke will
teach a Dried Arrangement Class in February! More
information in the next Newsletter.

CHRISTMAS SALE

Again thanks are due all the volunteers who planned, set
up, staffed and dismantled the Christmas Sale. It was a huge
success for it is getting to be a Denver tradition to shop at
the Gift Shop for unusual, intriguing items from all around
the world.

Thanks too to Avalonne Kosanke, Fran Morrison and
their helpers for the smashing Christmas display in the
Lobby Court which complements the poinsettias most
effectively. How do you think of something different every
year!

If you can’t decorate your home in quite that style
maybe you’d like to be more traditional with holly, ivy and
mistletoe.

Holly symbolizes the spirit of Christmas and is cele¬
brated by many carols for its glossy green leaves and red
berries. It also is valued as a charm against witches and their
evil machinations. Ivy is used to symbolize confiding love
and friendship, no doubt because of its clinging habit.
Mistletoe is more often associated with the Druids rather
than the Christian celebration. In fact the Church never
sanctioned it but popular usage did. It is not a beautiful
plant but because of its peculiar qualities many myths have
been told concerning it.

Holly generally doesn’t grow well in Denver but three
examples may be seen at the Denver Botanic Gardens: Ilex
meservae is planted near the garage at 909 York;/, cassine is
in the Conservatory and the true holly I. Aquifolium is
planted in the greenhouse. Ivy of course is widely planted
and the holiday mistletoe may be found in many shops and
stores.

AND MORE ABOUT IVY!

An enormous mess! That’s how Hedera nomenclature
has been described to readers and home gardeners in recent
years. Once people discover there are five species of Ivy, and
that the same plant (cultivar) is called by half a dozen
different names at six different garden centers — or named
simply “English Ivy” at all of them — they give up!

Small wonder. To correct this confusion, the American
Ivy Society (AIS) was charged with the National Registration
Authority for the genus Hedera. At its next meeting, the
Nomenclature Committee of the International Society of
Horticultural Science will consider charging the AIS with
International Authority.

The AIS has its headquarters at the National Center for
American Horticulture, Mt: Vernon, VA (22121). At the AIS
Research Center in La Plata, MD (20646), horticulturist
Henri K. E. Schaepman (current President of the AIS) has
been conducting experiments and researching all published
materials on Ivy, in an effort to determine the correct names
of the hundreds of cultivars of Hedera. The Research Center
has more than 200 distinct cultivars under study.

“It will be our responsibility,” says Schaepman, who
received degrees from the Horticultural College of Fredrik-
soord, The Netherlands, “to maintain the Register
accurately, and to register all new cultivars.”

The Ivy Society, which puts out a quarterly Bulletin for
its international membership, recently published a “Prelimi¬
nary Checklist of Cultivated Hedera, Juvenile Varieties.” It
contains more than 400 entries, with their names and
synonyms (sometimes as many as six), descriptions, sources
and characteristics. This unprecedented Ivy Checklist is
available for $5, to cover printing and mailing costs.

“It is a ‘Preliminary’ listing,” emphasizes Schaepman,
“because we are relying on the input and cooperation of
experts and tradesmen to enable us to produce the final
version. We’re anxious to reach and hear from as many
people as we can — through AIS membership or use of our
facilities, by both amateurs and professionals.”

The AIS invites people who deal with Ivy to avail
themselves of this opportunity to inform their clients of the
correct names and care of their Ivies, to contact the Society
with questions or identification problems (We’ll try to
identify the cultivars from cuttings — 10 leaves minimum”),
or to submit for registration new or unnamed Hedera
cultivars.

Correction

If you wish to go on a centennial tree walk as
mentioned in the last Green Thumb magazine the sugar
maple will be found in the 2300 block of Colorado Boule¬
vard. Also A1 Rollinger knows that Fagus is “beech” not
“birch” as printed.

A donation to the Kathryn Kalmbach Herbarium has
been received in memory of Mrs. William P. Mellen. Other
donations have been received in memory of Mrs. Gilbert
Davis and Mrs. Grace Ramsay. Thank you very much.

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4-HER'S ATTEND HORTICULTURE
CONVENTION IN PENNSYLVANIA

by LecClier Smith

Eight Colorado 4-H members recently attended the
National Junior Horticulture Association’s Convention in
King of Prussia, Pennsylvania. The eight all won the right to
attend the Convention representing Colorado by participating
in the State Contest in September at the Botanic Gardens.
Members competed in both the 4-H and Honors Division.
The contest is similar for both divisions, with eight classes of
judging fruits, vegetables, ornamentals, and flowers, an
80-question objective test, and identification of 100 speci¬
mens (160 for the Honors contest). Members of the 4-H
team were Keith Williamson (Logan County), Eric Umbreit
(Jefferson County), LecClier Smith (Arapahoe County), and
John Peasley (Alamosa County). Colorado Horticulture
Research, Inc. sponsored the trip for the members of the
4-H team. Competing in Honors were Steve Hadden, Robert
Zemanek, William Zemanek, and Julie Schmeeckle, all Logan
County. At the National contest the 4-H team placed
seventh out of 17 teams, while the Honors group did very
well with Steve Hadden placing fifth and Robert Zemanek
placing fourth individually. Robert Zemanek also gave an
illustrated talk on Landscaping at the National Contest.

In addition to participation in the National Contest, the
trip to Pennsylvania gave us the opportunity to learn a lot
about horticulture. Workshops were held on such various
topics as horticultural careers, hanging gardens, and plant
propagation. We also toured some local Pennsylvania
specialty greenhouses growing roses and mushrooms. The
highlight of the tours definitely was a visit to Longwood
Gardens with its beautiful grounds and fascinating indoor
conservatories. We also had some time to see the historic
sites of Philadelphia.

Having returned from this year’s convention with great
enthusiasm, we are already planning for more activities of
the Colorado Junior Horticulture Association and on attend¬
ing next year’s convention in Winston-Salem, North Carolina.

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HERB GARDEN PLANNED
FOR NATIONAL ARBORETUM

It was recently announced that the Herb Society of
America will build a $250,000 herb garden at the National
Arboretum in Washington as a bicentennial gift to the
American people.

The garden will contain a formal “knot” garden with
plants arranged in intricate patterns resembling various kinds
of knots. Also planned are specialty sections containing
herbs used for medicines, flavoring oils, dyes, teas, herbs
used by Indians and early colonial settlers and herbs that
attract bees. Species roses — the old fashioned nonhybrid
types — will also be featured in a special section.

The actual herb plantings are expected to occupy less
than one acre, including walkways and terraces, and a
background of various shrubs and trees. The garden’s size
and layout will permit it to accommodate fairly large groups
for visits and study. The Arboretum, which is part of the
Department, will expand its educational programs to include
herb culture and uses.

The Society had wanted to build the herb garden for a
number of years, but it was not possible until recently when
legislation was passed permitting USDA to accept gifts on
behalf of the Arboretum, and making the gifts fully tax
deductible.

Detailed plans for the herb garden are being prepared,
including a specific sequence of construction stages and
timetable for completion of each stage. The first stages of
the garden are expected to be ready for viewing in mid¬
summer of 1977, the year the Arboretum celebrates the
50th anniversary of its founding.

The free film on December 1 1 in Classroom C at
1:30 p.m. is entitled “Gardens of San Simeon.”
Spectacular photography highlights the beauty of these
gardens south of San Lrancisco. All welcome.

Green Thumb Newsletter is published monthly by Denver Botanic Gardens,
Inc., 909 York Street, Denver, Colorado 80206. The Newsletter is included as a
benefit of membership in the Denver Botanic Gardens, regular membership dues
being $ 1 0.00 a year. Items for publication are welcome. The deadline for copy to
the editor is 2:00 p.m. on the 10th of each month preceding publication.

Editor — Margaret Sikes — 297-2547