Washington Park Arboretum Bulletin Published quarterly by the Arboretum Foundation for the Washington Park Arboretum Washington Park Arboretum The Arboretum is a 230-acre living museum displaying internationally renowned collections of oaks, conifers, camellias, Japanese maples, hollies and a profusion of woody plants from the Pacific Northwest and around the world. Aesthetic enjoyment gracefully co-exists with science in this spectacular urban green space on the shores of Lake Washington. Visitors come to learn, explore, relax or reflect in Seattle’s largest public garden. The Washington Park Arboretum is managed cooper- atively by the University of Washington and Seattle Parks and Recreation; the Arboretum Foundation is its major support organization. Graham Visitors Center Open 10 am— 4 pm daily; holidays, 12 noon — 4 pm. Closed Thanksgiving and the Friday after, Christmas and New Year’s Day. University of Washington The University of Washington manages the Arboretum’s collections, horticultural programs, facilities, public information & education programs through its Center for Urban Horticulture. 206-543-8800 voice / 206-325-8893 fax Office hours: 8 am — 5 pm weekdays http ://depts .Washington . edu/ wpa Washington Park Arboretum John A. Wott, Ph.D., Director Center for Urban Horticulture Thomas M. Hinckley, Ph.D., Director Seattle Parks and Recreation The City of Seattle owns the Arboretum’s land, including the buildings. Seattle Parks and Recreation is respon- sible for routine maintenance within the Arboretum and manages and operates the Japanese Garden. 206-684-4556 voice / 206-684-4304 fax Ken Bounds, Superintendent Washington Park Arboretum Bulletin Arboretum Foundation The Arboretum Foundation is a nonprofit organization established in 1935 to ensure stewardship for the Washington Park Arboretum, and to provide horticul- tural leadership for the region. The Foundation provides funding and volunteer support for the mainte- nance, development and renovation of Arboretum gardens and collections and for education programs. Volunteers operate the gift shop, conduct major fund- raising events, and further their gardening knowledge through study groups and hands-on work in the green- house or grounds. 2300 Arboretum Drive East, Seattle, WA 98112 206-325-4510 voice / 206-325-8893 fax 206-726-1954 — events hotline gvc@arboretumfoundation.org orgsites.com/wa/arboretumfoundation/ Office hours: 8:30 am — 4:30 pm weekdays Gift shop hours: 10 am — 4 pm daily Officers of the Arboretum Foundation Board of Directors Deborah Andrews, Executive Director David E. Hervey, President Cynthia Duryee, Vice President Fred Isaac, Vice President Mike Allen, Secretary Kate Roosevelt, Treasurer Sherrill Elliott, Immediate Past President Lee Cuninggim Neff, Constance Bollen, Editor Graphic Design Joy Spurr, Photography (unless otherwise noted) Editorial Board Tom Berger, The Berger Partnership, Landscape Architects Pam Colangelo, Parsons Public Relations Jeannine Curry, Arboretum Foundation Richard W. Hartlage, Elisabeth C. Miller Botanical Garden Daniel J. Hinkley, Heronswood Nursery Joan Hockaday, Author Steven R. Lorton, Northwest Bureau Chief, Sunset Magazine Ciscoe Morris, Horticulturist, Seattle University Jan Pirzio-Biroli, Arboretum Foundation David Streatfield, UW Dept. of Landscape Architecture Bryan Taulbee, Arboretum Foundation Eleanor Thienes, Landscape Designer Brian Thompson, Elisabeth C. Miller Library, CUH Cass Turnbull, Plant Amnesty Founder Martha Wingate, Writer Botanical Editors Randall Hitchin, Registrar and Collections Manager Jan Pirzio-Biroli Martha Wingate For a rate card or other information about advertising in the Arboretum Bulletin , please call the Foundation office, 206-325-4510. Summer 2001 Volume 63. Issue 2. © 2001 The Arboretum Foundation. ISSN 1046-8749. Co N 2 An Odyssey — Deborah Andrews and John A. Wott 3 Turkey 2000: Plant Hunting in the Pontic Alps — by Daniel J. Hinkley and Richie Steffen 5 HORT 101 A Glossary of Horticultural Terms 10 Venus versus Mars — Ciscoe Morris 12 Just Call Me Zeus — Mary Morris TENTS 14 Tales of Enarmonia formosana-. Tracking the Cherry Bark Tortrix — Lynell K. Tanigoshi 16 Managing Cherry Bark Tortrix at Washington Park Arboretum — Christina Pfeiffer 18 The Layered Way — Barbara Selemon In a Garden Library: 23 A True Treasure Trove — Brian Thompson, Bulletin Book Review Editor 26 Nature is visible, art concealed — Charlotte A. Tancin ABOVE: Magnolia grandiflora, the Southern or bull bay magnolia, is native from North Carolina to both Florida and East Texas. It has large, thick, leathery leaves and eight-inch, creamy white, fragrant flowers from May through August. In the Arboretum it may be found at map grids 27-3E, 27-4E, and 30-B. ON THE COVER: Located just west of Arboretum Drive E., between the Japanese maple collection and the Witt Winter Garden, this giant Thuja plicata (Western red cedar) stands sentinel over intrepid explorers who venture up these woodland steps. Summer 2001 ^ 1 The Arboretum's footbridge, a fine place for a cool stroll on a warm, summer day. An Odyssey | hen we began to work on the Arboretum’s master plan, over seven years ago, we had no idea we were embarking upon such a lengthy journey. Like Odysseus, on his trip home to Ithaca, the master plan has had myriad adven- tures. And like Odysseus, after taking a number of rocky detours and listening to much well- meant advice, the plan is finally almost home. This issue of the Bulletin goes to press at the tail end of “a long, difficult, though we think productive, journey,” as Fred Issac, Arboretum Foundation Vice President, termed it. And no wonder! The plan, a $46 million proposal that includes four new buildings, the expansion of plant exhibits from 30 to 51, and Arboretum-wide staffing from 23 to 72, required careful scrutiny and thoughtful adjustment in order to reflect the druthers of a widely diverse and highly invested community. Over the past few months, the plan was approved unanimously by the Seattle Board of Parks Commissioners and the Culture, Arts and Parks Committee of the Seattle City Council. In May there were final votes from the entire Seattle City Council and the UW Board of Regents. With approval, we can all embark upon the new 20-year pilgrimage required to achieve the plan’s goals. In the years ahead, the Bulletin will keep its readers apprised of the many adventures required to complete the journey. We hope to have you with us for the entire trip! Deborah Andrews, Executive Director, Arboretum Foundation John A.Wott, Director, Washington Park Arboretum 2 Washington Park. Arboretum Bulletin A rare, sunny day blesses a twenty-acre swath of Colchicum speciosum at peak blossom on a high pass directly south of Trabzon. Since the seed had dehisced from the carpels many weeks earlier, seeds from this population were successfully extracted by sifting the soil beneath each plant. In the late summer of 2000, Bob Beer, a local plant enthusiast, Dan Hinkley and Richie Steffen teamed up to examine the flora of Northeast Turkey. In this article, Hinkley and Steffen share memories of the plants THEY ENCOUNTERED DURING THEIR MONTH-LONG EXPLORATION. Turkey 2000 IB Dan Hinkley: We followed a more or less circular route, from Trabzon, on the Black Sea, east toward Turkey’s border with Georgia. Here we turned south, up and over the Pontic Alps toward Artvin, returning to Trabzon along the parched backside of this range, traveling west along the Coruh River Valley. In the course of four weeks, we were exposed to numerous weather niches and microclimates, from the wettest valley of Turkey near Rize, which receives 13 feet of rain per year, to semi-arid, wind-swept passes clad in swaths Summer 2001 ^ 3 DAN HINKLEY DAN HINKLEY Turkey 2000 continued Chat, Turkey. A Byzantine ruin surrounded by a forest of Picea orientalis. This part of Turkey was conquered by the Ottomans in the early 15th century, bringing to an end the 700-year rule of the Eastern Roman Empire. of autumn blossoming Colchicum and Crocus. All the while, we encountered the fertile and historical blend of Byzantium, Ottoman and Islamic cultures and enjoyed an enormous contingent of outgoing and friendly Turks. Rhododendron luteum ■ Richie Steffen: Our first day of exploration brought us to the small village of Hamiskoy near Zigana Pass. It was a cool, clear, sunny day, and we were anxious to see what we could find. We scrambled up the grassy mountainside, finding a rich array of plant life. I had barely reached the top of the steep road cut before spying one of the plants I had come to Turkey to see, Rhododendron luteum , one of the best flowering shrubs in the region and the first of five Rhododendron species native to Turkey. Rhododendron luteum is unique in that it is the only deciduous Rhododendron species native to Europe. Its bare branches erupt in a profusion of bright, rich yellow flowers in late April, filling valleys with the heady fragrance that local people sometimes find truly intoxicating. Rumor has it that honey made from these flowers can have a toxic effect; in fact, such honey is reputed to have stopped, or at least slowed, the advance of Greek and Roman armies. We often found broad thickets of R. luteum growing on the slopes of the coastal mountains. Most of these plants had the typical dark green foliage, but in high elevation populations we would occasionally find individual plants with glaucous-blue leaves. In a few locations we found exceptional forms with almost sky-blue leaves. Picea orientalis & Companions ■ Hinkley: On the moist, northern slopes of the Pontic Alps, on jagged rocks that thrust over a mile above the sea, is a patchwork of greens that I have never before experienced. The verdant, finely textured shag of the loveliest of all spruces, Picea orientalis, provides the background for an enormous range of plants grown in Northwest gardens. Picea orientalis is one of the best species of this genus for cultivation in our climate, for it resists the aphids and mites that plague other spruces. At lower elevations, the hornbeam, Carpinus betulus, adds a stately presence, demonstrating a slender habit of growth in its youth — in fact, growing even narrower than the commonly encountered ‘narrow’ European hornbean, Carpinus betulus ‘Fastigiata’, that we coppice in our Heronswood garden. As one progresses higher in elevation, Fagus orientalis, or the Pontic beech, whose elephantine trunks slice the mountain vertically with slashes of silver-gray, is partnered with continued on page 6 4 Washington Park Arboretum Bulletin HORT 101 Test your horticultural vocabulary with these terms used in this issue! CALLUS, (kal'as), noun The tissue that forms over cut or damaged plant surfaces, protecting the inner tissue and allowing healing. CLASSICAL BIOLOGICAL CONTROL The discovery, importation and estab- lishment of exotic natural enemies to reduce the economic impact of an exotic pest. DEHISCE, (di his ), v.i. To burst open, as a plant’s seed capsules burst when seed is ripe. FRASS, (fraes), noun Solid larval insect excrement. HOST, noun The organism in or on which a parasite lives. INDUMENTUM, noun A covering of hair or, more rarely, scales. MONOCOT, (mon'a kot'), noun, MONOCOTYLEDON A plant of a subclass of Angiosperms characterized by an embryo containing a single seed leaf and floral parts in multiples of three including grasses, orchids and lilies. OVIPOSITOR, (o'va poz'itar), noun In certain female insects, the organ at the end of the abdomen through which eggs are deposited. PARASITOID, (par' a si toid'), noun An insect that hatches within a host, feeds on it during the larval stage, and becomes independent when the host dies. PHEROMONE, (fer'a mon), noun A chemical signal or scent emitted by insects and other species as a means of communication. For many insects, pheromones are used to attract mates. To monitor insect population levels by attracting male members of the species, pheromones can be artificially produced and placed in a sticky trap. PYRETHROID, (pi re throid), noun A synthetic chemical similar in structure to botanical insecticides extracted from chrysanthemum flowers. THE ROYAL HORTICULTURAL SOCIETY: Founded in London in 1804 to collect cultural information especially on culinary and ornamental plants, the RHS is now regarded as one of the world’s leading organizations in the testing of plant varieties and gardening practices and the preserva- tion of horticultural resources. Particularly noted for the Chelsea Flower Show, the RHS gardens at Wisley (near London), and the monthly journal “The Garden.” STOLON, (sto' Ian), noun A horizontal stem growing along the ground that may form roots for new plants at its tip or at nodes. Summer 2001 °*> 5 DAN HINKLEY Turkey 2000 continued Picea orientals is the coniferous component of the climax forest throughout this area of Turkey. In the Pacific Northwest, its handsome, finely textured foliage is resistant to damage by both aphids and mites. the spruce to form the heart of the Turkish flora. This pair is found again and again, but with different associates in tow. If one wishes to find good plants, one simply needs to find the two together. Fagns orientalis is infre- quently found in cultivation and is intermediate in habit between F. sylvatica, the European beech, and F. crenata, the Japanese beech. It features large and handsome leaves up to five inches in length held along smooth, silvery, pachy dermal stems to 100 feet or more. There are two specimens in the Arboretum near the north end of Azalea Way. Rhododendron ponticum ■ Steffen: Where Rhododendron luteum was found, we almost always found R. ponticum. Its resilience was amazing. Individuals grew in both full sun and full shade, from sea level to the mountain passes. It seemed only to be limited by the biting cold of the mountain peaks and the aridity of the southern slopes. It is no wonder that it can survive neglected landscapes throughout the Northwest! Driving along winding roads, we could see Rhododendron ponticum creating an impene- trable tangle covering entire mountainsides. In lower elevations, these thickets were 15 to 20 feet in height, while at the passes, dense mounds barely reached three feet. I found it easy to imagine the entire region glowing, in spring, with pinky-purple and lavender blooms covering the mountain slopes. Osmanthus decorus & Prunus laurocerasus ■ Hinkley: Another noteworthy evergreen that is widely present in Turkey is Osmanthus decorus , too infrequently grown in Northwest gardens. From light brown stems rising to six feet, grow pairs of long and narrow, leathery, deep green leaves, and in early spring, clusters of fragrant white flowers are produced in the leaf axils. In cultivation, this shrub is remark- ably adaptable. I have seen it growing in hot, baking, non-irrigated conditions as well as in deeply shaded sites; in both positions, it performs admirably. In Turkey we found it growing primarily in shaded sites of moder- ately dry soils, often clinging to steep rock faces. Unfortunately, we did not find a single fruit on the countless specimens we scoured. At higher elevations, Prunus laurocerasus, the cherry laurel, was present in a form that would be unrecognizable to most of those growing it in the Northwest, where it is frequently utilized as an economical, fast- growing hedge. In Turkey it created thickets that were discernible by the sheen of its foliage as well as the masses of blue-black fruit that were just ripening. Large fruiting varieties of this species are cultivated throughout the area, and the ha west was visible in numerous fruit stalls in the villages we visited, often sold side 6 Washington Park Arboretum Bulletin ■ Steffen : Almost every day, at about one o’clock in the afternoon, clouds would roll in from the Black Sea creating a misty fog in the mountain passes. One of my most memorable experiences was finding Rhododendron cauca- sicum in one of these mountain mists. The scenery was surreal: a sparse forest of stunted spruce and fir with rhododendron thickets in between. True R. caucasicum with its pale yellow or pink-flushed flowers is rare in culti- vation and challenging to grow. As we wandered through dense thickets of these rhododendrons, imagining them in bloom, we found the rare Epigaea gaultheri- oides, the larger-flowered, Turkish counterpart of eastern North America’s trailing arbutus, Epigaea repens. The Turkish arbutus is a low, evergreen shrub with soft pink flowers and new growth covered in fine, red, bristly hairs. Luckily, I have been able to germinate seed and hope to establish this difficult plant in the landscape. Gentians & Geraniums ■ Hinkley: Approaching elevations of 4,000 feet or more, we were greeted by masses of Gentiana asclepiadea , the willow gentian. “Sensational” would be a barely adequate way to describe this exquisite species. Arching stems to three feet cany elegantly narrow, willowy leaves to four inches while tubular flowers in shades of indigo blue to white are carried along its entire length in very late summer. We observed a vast degree of varia- tion in color throughout separate populations, though unfortunately, we were able to collect Rhododendron luteum 'Golden Comet,’ a cultivar selected, named and available at the Rhododendron Species Foundation. very little of its mostly unripe seed. This species is a superb choice for the Northwest — long-lived and dependable in blossom for partial shade or full sun in any moderately moist soil. Often growing in association with this gentian was the superb and zippy flowered Geranium psilostemon. Its vibrant, magenta- pink flowers, centered with a contrasting black-purple spot, are carried on rather lax stems to 18 inches. Even in early autumn, this species was offering quantities of flowers. Another cranesbill observed, though not as commonly, was G. platypetalum with large, felted, gray-green leaves and deep lavender, cup-shaped flowers. Roy Lancaster’s well- known selection, 'Georgia Blue,’ was collected in the Caucasus, whose sharp, snowy peaks we occasionally saw jutting above the dusky water of the Black Sea. Both geraniums are now quite commonly encountered in Northwest gardens, though in a relative sense, they are still quite new. Summer 2001 7 KEITH WHITE DAN HINKLEY Turkey 2000 CONTINUED The almost translucent, pale pink blossoms of Colchicum speciosum. Rhododendron ungernii ■ Steffen: A mountain located on the Black Sea about twenty-five miles from the Georgian border, Savaltepe is the place to see rhodo- dendrons in Turkey. All five Turkish species grow and thrive on this mountain, as well as some interesting natural hybrids. The base of the mountain was relatively dry and arid, similar to the east side our Cascade Range. As we gained elevation, the air became cool and moist, and plant life flourished. We stopped for lunch and happened to picnic near a patch of the rarest rhododendron in Turkey, Rhododendron ungernii. This interesting species has large, dark green leaves reaching 10 inches long and three to four inches wide with thin, white indumentum. This first patch, growing in full shade, was composed of plants topping out at 12 to 15 feet; later we found plants growing in almost full sun but seldom over five feet tall. Flowers tend to be white to pale rose pink on a compact truss. Although the truss is small, the mid-summer blooming time compensates for its size. In the Pacific Northwest, Rhododendron ungernii would typically bloom in early to mid-July! Precious Perennials ■ Hinkley: During the course of our travels, we were able to collect seed of several species of Primula, though it will be at least a year before we will be able to say with certainty what they are. Amongst them we expect P. veris, the common cowslip native to much of Europe and a lovely species still too infrequently used in our gardens. The intensely fragrant flowers of yellow (and occasionally red) are proffered in late winter atop eight-inch stems. Certainly other collections will prove to be P. vulgaris var. sibthorpii, which we have cultivated in our garden for some time. These cheery flowers of medium lavender are produced above rather lusty mounds of green foliage in late February and prove again and again to be the earliest of the genus. It is considered to be one of the few Primula able to withstand the humid condi- tions of southeastern United States. Among my passions is the genus Epimedium , and it was certainly the prospect of seeing these in the wild that had encour- aged me to wander this far from home. We ultimately were able to find numerous sites of E. pubigerum that showed a great deal of variation from population to population. The elegant, leathery evergreen leaves were carried along stems to two and a half feet in some instances, while the small, normally white flowers are carried on panicles above. Due to the paucity of genetic material of this species in cultivation, we are most interested in observing the variation in flower color when these collections ultimately blossom. Another plant I hoped to observe was a Trillium relative known as Paris incompleta. Though the hotbed of the genus is in China, where numerous ornamental species exist, this is the only representative to be found in 8 ^ Washington Park Arboretum Bulletin Eastern Europe. We ultimately were able to find this species growing at higher elevations than we had expected, always associated with Fagus orientalis. Paris incompleta is composed of an elegant whorl of narrow leaves carried on stems rising to 15 inches, with quiet flowers of green sepals and no petals (hence the specific epithet, incompleta). The Paris grew side by side with a baneberry, Actaea spicata, a striking member of the Ranunculaceae. Very similar to our native, red-fruited Actaea rubra , frequently encountered in woodlands of the Puget Sound, this species possesses large heads of glistening black fruit, following racemes of white flowers in spring, held above mounds of deeply divided foliage. The genus Actaea is closely related to the bugbanes, Cimicifuga species; in fact, recent research indicates that these are one in the same. Rhododendron smirnowii ■ Steffen: We saw the fifth Rhododendron species, R. smirnowii , at tree line. A medium- sized plant, reaching about five feet tall in 10 years, R. smirnowii is a great plant for the garden. Its leaves are dark green with a soft, thick, woolly indumentum. The compact flower trusses bloom in May and range in color from soft pink to deeper purple-pink. It is both hardy and able to withstand drought. As we climbed the slopes, we found a few plants with a light cinnamon indumentum, much darker than the usual fawn color. Having collected seed of these forms, I am patiently waiting the five years it will take before the indumentum shows on the seedlings. Colchicum speciosum ■ Hinkley: During our trip’s last days, Colchicum speciosum , which we had seen as Rhododendron smirnowii, this one a rich lilac. occasional individuals at high elevation, came into full blossom, and we were treated to acres of this remarkable species, showing inconceivable variation in flower color, shape and size. Spending the afternoon together on that hillside, seduced by C. speciosum s rich color and variety, will long remain seared in our memories. Due to its uniquely delineated wet and dry microclimates, Turkey has an astoundingly large and diverse flora. Of this, we witnessed a minute fraction of what exists within its borders. Still, we saw enough to celebrate the astonishing diversity of plants that have found their niche in every nook and cranny of this remarkable corner of our planet. Richie Steffen is the Coordinator of Horticulture for The Elisabeth C. Miller Botanical Garden. Dan Hinkley is Director of Heronswood Nursery, which he co-founded with Robert Jones in 1987. Half of all tour fees collected at Heronswood during the 2001 gardening season will be donated to the Eastern Black Sea Forestry Research Institute to help aid study of the endemic flora of this region and the preservation of its bio-diversity. Summer 2001 9 ART DOME ILLUSTRATION WENDY WAHMAN Venus versus Mars By Ciscoe Morris o you feel unfortunate because your partner is a lazy bum who won’t help you in the garden? An contraire, you are one of the luckiest people in the world because you get to do whatever you want! I had the misfortune of marrying an outstanding gardener. Don’t get me wrong. I’m crazy about my wife Mary. We have a wonderful marriage and get along great... until it comes to gardening! When we go out to garden together, we barely make it five feet out the door before the argument starts. Where I want to plant a Lobelia Dark Crusader’, she wants a Lignlaria stenocephala ‘The Rocket’. Neither of us is willing to give an inch, and the next thing you know, we are once more entertaining the neighbors, jumping up and down, arms flying wildly in the air. It is yet another garden war. It got so bad at our Beacon Hill house that we finally had to divide the garden right down the middle. She got her side, and I got mine. Whenever someone came to visit, we’d stand shoulder to shoulder, demanding to know: “Which side do you like the best?!” I admit that at our present house, got the jump on front-yard space when we moved in 15 years ago. It wasn’t my fault. There were some big dying trees that had to be removed, and since I happened to have a backhoe at home, it just made sense to bring in a few boulders to fill the voids. Naturally the stones looked silly standing there by themselves, so I filled in with plants right away. I can’t see how she can possibly call me an imperialist for that! Besides, while I was working away in the front, she was busy annexing most of the backyard. It was totally unfair of her to greedily gobble up all of the good garden space while I was just making sure that the front looked good for our new neighbors. It might seem odd that my wife Mary and I can’t garden together, but admitting it really has saved a lot of money visiting Marilyn (our marriage counselor). I like having my own territory' where I can do whatever I want. ..well, almost whatever I want. I’m banned from bringing home boulders and backhoes since the time I put the ton-and-a-half stone through the side of the house and followed it with the bulldozer. Hey, so I made a little slip-up. Anyone could have done that! I won’t try to pretend that simply dividing up the garden has solved all marital difficulties. The problem now is how to share uncharted temtory. For instance, I wanted to take out a little corner of the lawn to make a new garden in the front yard. After three weeks of gmeling negotiations, I finally obtained my new garden, but it cost me big time. I relinquished all control over the veggie garden and have suffered an acute Brussels sprouts shortage ever since! I have to be constantly on guard. Mary is 10 Washington Park Arboretum Bulletin always tiying to trick me into giving her some of my garden space. She actually tried to make me feel guilty, claiming she doesn't ever see the neighbors since most of her gardens are in the back. Nice try, but I’m not noodle- headed enough to fall for that maneuver. However, her constant complaining wore down my defenses. She took advantage of my desperate need to find a place for a whole flat of rarities from Heronswood Nursery that needed to be planted tout de suite. Somehow, I traded my future rights to half of the parking strip for a much smaller space that opened up when we tore out an old camellia. I was tricked! In a day my little spot was full, and she has the whole parking strip under her control. This could call for a trip to Marilyn! Worst of all, we’ve become quite compet- itive. When we go to a nursery together, we are constantly competing to find something cool before the other one sees it. We rarely will stoop to buying the same plant, so it is generally first come, first served. Last summer, we were in one of our favorite nurseries when we both noticed for the first time, a gold- leafed bacopa ISutera cordata ‘Olympic Gold’). This time it was definitely “finders, keepers.” There was only one left on the shelf! We both pretended not to see it and began to move surreptitiously toward the treasure. Within seconds our mutual attempt at subterfuge deteriorated into a roller derby-like headlong rush. Customers ran for cover as we elbowed and blocked each other in an attempt to win the prize. Mary beat me by an inch, making an incredible diving grab as she crashed into the shelf. I watched her stmt her stuff while gleefully showing me her trophy. (Now I understand why the NFL has banned touch- down celebrations!) That evening, since I was running late to give a garden talk, I reluctantly (against my better judgment) agreed to let Mary divide up our new plants. When I checked my box of plants, at nearly midnight, just to make sure that Mary didn’t abscond with any of my best finds, I almost fainted. Somehow she had failed to notice the gold-leafed bacopa; it was in my box! Without a moment’s hesitation, I ran for the shovel. It was pitch dark, but somehow I got it planted in one of my key gardens. I noticed several neighbors looking out their windows, undoubtedly wondering what I was up to. They found out the next morning when they heard Mary’s blood-curdling scream (and a few choice words). I don't know why she got so upset. How was I supposed to know it wasn’t my plant? It was in my box, so naturally, I thought it was mine. Besides, you should see how great the golden foliage looks with my shrubby, red-leafed Clematis ‘Lime Close.’ She can’t possibly really want to go see Marilyn over a little thing like this! Yes, dividing up the garden doesn't solve every marital problem. However, I wouldn't trade any of our battles if I had to give up the closeness we share when we stroll together to admire each other’s work at the end of the day. That’s when we walk, arm in arm, show off new acquisitions, compliment incredible plant combinations, and cringe at a few color compo- sitions that are just a wee bit too daring. As we wander together, enjoying the hummingbirds and butterflies, I am consumed with an overpow- ering attraction. Actually, what I’m attracted to is the large, new garden space that I suddenly realize Mary has created by removing an old tree and some shrubs in the back of one of her gardens. Now that I think about it, it’s only fair that I should have that area since she is getting the whole parking strip. In fact, it's not only a matter of fairness; it would be a magnanimous gesture for me to take over this space. Planting that big parking strip will undoubtedly tax her strength. I think we had better discuss this. Ooh, la, la! How come I have that funny feeling that I am about to see Marilyn again...? Ciscoe Morris is the Horticulturist at Seattle University. He produces and hosts a popular Saturday morning gardening program on K1RO radio. Summer 2001 11 ILLUSTRATION WENDY WAHMAN Just Call Me Zeus By Mary Morris hose who are intrigued by Ciscoe’s radio show, garden talks, and lively personality tell me that I am a lucky woman to be married to him. Those who know Ciscoe and his eccentrici- ties offer me their sympathies. Yes, he is eccentric and passionate about his plants and gardens. Fortunately, I share his gardening passion. Unfortunately, we share a finite amount of garden space. After attempting peaceful gardening side-by-side, we realized that it was hopeless. Now we don’t pretend to look for resolution to our marital gardening woes; we just “divide and conquer.” He gets his space; I get mine. Here I offer my top 10 tips to those in the same predicament. 1. Money is no object. Buy the newest and greatest plants for ^ your gardens. You'll drive your partner mad with desire (not for you, for the plants)! One week after I acquired a spectacular new Fuchsia ‘Preston Guild,’ Ciscoe ventured to the' nursery where I bought it. As the nursery had sold out, he came home empty- handed. Secretly, I was delighted with my good fortune, while consoling Ciscoe in his misfortune. Every night when taking Kokie for her walk, I pointed out the brilliant, crisp white flowers on my ‘Preston Guild.’ 2. Measure the gardens to make sure you aren't getting short changed. What Ciscoe calls half is actually a three- fourths to one-fourth split in his favor. When I threatened to bring out the measuring wheel, he consented and handed over a bit more space. It’s still a far cry from half, but I’m gaining! 3. Make sure that you gain control over key areas. Nothing is worse than enjoying dinner on the patio when Ciscoe’s voodoo lily begins to bloom. May as well serve “Spam Surprise” to go along with that odor. Also, make sure you gain control over some of the “social hotspots.” I am often working in the back yard when I hear Ciscoe’s booming voice talking to every neighbor who walks by. Needless to say, at the end of the day I find that I’ve been more productive, but he’s had more fun. 4. Watch your partner closely to make sure that no garden encroachment is going on. Ciscoe considers my gardens his test gardens. One day I walked out the door to find Ciscoe digging into my (dormant) prized hosta, ready to plant a new acquisi- tion in my garden. His attempt to explain himself? “It’s a surprise for you, and uh, uh, you look really nice today.” 5. Plead ignorance when it comes to power tools. Ciscoe is a pro at this 12 Washington Park Arboretum Bulletin little trick. As he was running an aerator one day, he suffered a geezer moment and forgot which control stopped it. Luckily for him, he remembered an inch before aerating my Toyota. Now, after years of mowing, edging, and the occasional aerating, I realize the virtue of ignorance. Come to think of it, perhaps you should have conceptual diffi- culties running the vacuum cleaner as well. 6. Don’t ever do anything to improve your partner’s garden. My mom visited me one day and pointed out an unsightly dandelion in the garden. She said, “Look at that big weed!” I replied, “Yes, I’ve noticed it for days, but that’s Ciscoe’s garden”. Of course it works in reverse as well. After hearing Ciscoe brag to radio listeners about going out late at night to weevil hunt, I suggested that he put the “el- kabatsky” on the little pests in my garden. But alas, he refused to pinch my weevils. 7. Don’t expect help with a task. Ciscoe is not one to dig the hole for me. I told him one day that I might need his help taking a tree out. He agreed, but said he was busy setting up his new fountain. I began to dig my tree out. After 10 minutes had passed, I heard Ciscoe’s voice: “Mar, can you hold something for me?” I went over to hold the base of the fountain, then returned to my digging job. Another 10 minutes.... “Mar, can you hold something for me?” Before the day was over, I had dug out my tree myself and spent most of my day helping him set up his fountain. 8. Plan your most productive gardening time when your partner is not home. Why? Ciscoe has banned me from using his prized and pricey gardening tools. When he’s not home, I raid the garage and find his chrome digging spade, chrome fork, and top-of-the- line hand pruners which are always cleaner and sharper than my own. I fear that he may be onto me because he recently asked me why his digging spade was covered with dirt. So, I fed him some Brussels sprouts, and he forgot about it. 9. Reconsider your plans to marry a gardener. How about a chef? Imagine all the delicious meals you could enjoy after a hard day of gardening. “Oh, this duck a Vorange is even tastier than the lasagne al forno you prepared last night. My, and is that creme brulee for dessert?” 10. Answer only to the proper title. I prefer Queen or Dictator. Zeus is also a fitting title: Forget about Venus and Mars. My theory is that the title will garner respect allowing me greater control of the garden. Sadly, it doesn’t really work, but it’s a pleasant fantasy. I must admit that the real figurehead is neither Ciscoe nor me but our four-footed beast: Queen Kokie. After all our struggles to garden together, is it too difficult to make it work with your gardener hubby? No way: Vive la competi- tion! Mary Morris works as a heart research analyst in the University of Washington Bio- Statistics Department. She and Ciscoe lead garden tours abroad and spend their free time hiking across the Alps and getting lost in the Andes. "Nothing is worse than enjoying dinner on the patio when Ciscoe's voodoo lily begins to bloom." Summer 2001 13 IHSOOINVX liaNAl TALES OF ENARMONIA FORMOSANA: Tracking the Cherry Bark Tortrix By Lynell K . Tanigoshi ave you seen this beautiful moth in your garden? I hope not! For it is Enarmonia formosana, the destructive cherry bark tortrix (CBT). Long known in Europe, this moth species was first reported in North America in the Richmond, British Columbia, region in 1989 and found established throughout the lower Fraser Valley and on Vancouver Island, Canada, in 1990. It was first detected in the United States in 1991 when two mature, ornamental cherry trees in the Peace Arch State Park, near Blaine, Washington, were found to be heavily infested. Washington State Department of Agriculture entomologist Eric LaGaza reported in his 1998 sex pheromone trap survey that, since 1995, CBT has expanded its range in the Puget Sound area south through Centralia, Washington. The Latin root of Enarmonia formosana’s species name, formos, means beautiful or graceful. And the adult CBT is indeed elegant, cryptically ornate, having a dark brown to black-purple sheen, yellow-orange markings and several white patches along the leading edge of its wings. CBT produces one genera- tion a year, and the adult flight period extends from May to September. This moth is classi- fied in the large family of leafrollers, insects that feed on a wide array of perennial plants A camouflaged adult cheny bark tortrix moth. 14 Washington Park Arboretum Bulletin Join us in supporting the Washington Park Arboretum , a living museum , a garden of discovery and an outdoor classroom. A Gift for the Washington Park Arboretum - a spectacular urban green space. H YES I wish to support the Arboretum Foundation with a gift of$ c o 0) g M-h O l-l O o c s C M X £ U U o o u n3 n n n , . CD • H C 4— » 0) <4-4 tn ‘5b 17 & ! JL -/Oui Hi w /. * \ m. '"-N— tr- m m ■„ • ■ ' ’ Mi 1 Clematis viticella ‘Betty Corning,’ a hardy, floriferous clematis which reaches its peak in late summer or early autumn, may be seen on the patio east of the Visitors Center. It is a fine candidate for simple or compound layering THE LAYERED WAY By Barbara Selemon LAYERING: The development of adventitious roots on a stem while it is still attached to the parent plant. Ihe rooted or layered stem is detached and becomes a new plant growing on its own root system. Do you have a favorite, old rhododendron that hasn’t been available in nurseries for years? One that you would love to give to your daughter when she moves into her first home? Or perhaps a much-admired clematis that you want to share with a friend who is learning to garden? Why not try layering them? Fortunately, plants have the ability to form “adventitious roots,” roots appearing in an unusual location, along their stem where the plant hormone auxin (a naturally occurring substance which promotes root growth) is accumulated in one spot. One can see this effect in nature where the tips of English ivy or Himalayan blackberry root when bent to the ground (tip layering). Other natural varia- tions of this phenomenon are seen in spider plant runners, carpet bugle stolons and offsets of monocots such as in the banana plant. The gardener can manipulate and layer plants in a similar fashion either by constricting the stem or excluding light from a growing area. Stem constriction of any sort interrupts 18 Washington Park Arboretum Bulletin the flow of auxin and carbohydrates from the terminal growing end downward, causing these materials to accumulate near the point of treat- ment. This promotes the initiation and subsequent development of roots. The exclu- sion of light to newly growing stems (etiolation) or to already formed stem tissue (blanching) is thought to decrease the amount of material deposited in the cell wall and to increase the number of actively dividing cells in the treated area, which assists in the initi- ation and promotion of roots. Simple Layering. Methods of stem constriction include A. twisting; B. girdling; C. creating a tongue. Methods of stem constriction: Bend stem upwards. Twist stem to rupture tissue. Girdle stem by removing a strip of bark all the way around. Create a tongue by cutting a 1-2 inch sliver and bending the stem (useful on brittle stems). Long Ago and Now Three to four thousand years ago, air layering, a method of producing new plants by aerial stem constriction and wrapping, was practiced in China. In the 18th, 19th, and 20th centuries, nurseries in Europe relied heavily on the practice of mound layering for fruit and nut rootstock production. The practice of layering plants became less favored as mist propagation and hormone applications became prevalent. Today, new plants are being produced using a biotechnological means of air layering through inoculation with a soil bacteria known to cause "hairy roots" at the site of treatment. Without resorting to this sort of sophistication, the home gardener may choose to propagate a large or rare plant in his yard by simple layering or to reproduce a new houseplant by air layering. The Basics In general terms, layering may be accom- plished three times a year: fall, late winter/early spring, or summer. The timing is determined by the flexibility of the stem being layered. There are three basic types of layering: a. Stem is lowered and placed into the soil (simple, compound, or tip layering) b. No soil covers the stem (air layering) c. Soil is mounded up along the stem (stool or mound, trench, or French layering) The home gardener may attempt layering a new plant if there is limited plant material available for taking cuttings, if there are limited resources for other methods of propagation, or if a larger plant is desired in a shorter period of time. Also, layering is a good way to increase certain grafted plants and plants that tend to sucker profusely. The soil used in simple and compound layering should drain well and consist of sandy Summer 2001 19 loam with 3 percent organic matter. The site needs to be located away from frost pockets and sheltered from winds. Irrigation must be available in the area so that the layer has adequate water to flourish. Layering may be carried out in a specified bed, which is typically raised from the ground, although layering in the landscape is acceptable — as long as the site chosen provides a good environment. Avoid planting in overly wet soils, which not only drain poorly but also may harbor many soil-borne pathogens. Heading back of plant LAYERING: SIMPLE TO CONTINUOUS Simple Layering: Used on a wide complement of woody plants. Examples: rhododendrons or magnolias The stem is constricted and pegged down during late winter. A cane is sometimes placed adjacent to the shoot and the stem tied to it to keep the shoot vertical. Serpentine or compound layering of Wisteria. Sufficient roots have developed along the stem by late summer to allow severing from the mother plant and lifting in the subsequent fall or winter. Shoots to be used for layering in the following year have been tied onto a pole. Timing: Early spring/summer using dormant one-year-old shoot material Stem constriction: Rhododendron (bent); Clethra (twisted) and Magnolia (tongued) Use low, flexible branches of plants that can easily be bent to the ground. Shoots that are layered in spring can be lifted in fall or the following spring. Branches that are layered in summer should remain in place until the following spring and harvested prior to new growth. Harvest timing: Ranges from two months ( Rhododendron ) to five months ( Cornus stolon if era) or longer Compound (Serpentine) Layering: Practiced on vines such as Wisteria, Clematis and Vitis Timing: Early spring or summer Essentially the same principles as simple layering apply except that several sections of stem are covered with soil to produce more than one new plant. Stems are twisted, girdled, or tongued and usually placed down in a circular fashion to save space. Pegs are placed in different areas so that vegetative buds are above the soil line. Harvest timing: New layers are obtained one year following treatment. (Grapes take two years.) 20 m Washington Park Arboretum Bulletin material to induce vigorous new growth of the branch being layered (except in rhododen- drons) is common. Harvesting of the newly layered plant usually occurs in the fall, four to six weeks after the severed cut is made from the parent plant. This allows for further root develop- ment and good establishment during the wetter months of the year. All layered plants should be treated as any other new plant, receiving irrigation as needed for the first three years after transplanting occurs. Layered tfb. Air Layering: Practiced on houseplants (tropicals) and some woody plants that are difficult to root Timing: April through August Stem constriction : Girdling or tongue An aerial stem is constricted 5-12" from the tip of the branch. A hormone application is made to the wound site. Materials (such as moistened peat moss) are placed around the wound area to provide an environment for inducing root development. An 8-10" square piece of plastic wrap is placed over the moss-covered stem area and secured with waterproof tape. Harvest timing: The aerial root is severed from the mother once roots are visible through the plastic. Aftercare: For a few weeks following the severance from the mother plant, place in a cool, humid environment in order to gradu- ally harden off the new plant. Mound Layering (Stooling): Practiced on plants that sucker easily and used for producing fruit tree rootstocks Timing: In spring, prior to new growth A stool bed is planted one year prior to the layering treatment. Mother plants are spaced out and the basal suckers of a young plant are covered over several different times during the year with a sandy loam soil. Harvest timing: In spring, one year after treatment tfe Trench Layering (Continuous Layering): Practiced mostly on woody species that are difficult to layer by the mounding method ', nurserymen use one-year-old saplings planted at an angle and then cover them entirely with soil. This procedure can also be conducted on established shrubs or trees at home by bending long flexible shoots or vines to the ground and burying them in a trench. DRAWINGS OF LAYERING TECHNIQUES COME FROM PRACTICAL WOODY PLANT PROPAGATION FOR NURSERY GROWERS. VOLUME 1, BY BRUCE MACDONALD, PUBLISHED BY TIMBER PRESS. USED WITH PERMISSION.. A. The stem is girdled (or tongued). B. A rooting hormone is applied to the cut surfaces and the area is then covered by a handful of moist sphagnum moss. C. A square of polyethylene is wrapped around the moist sphagnum moss. D. The polyethylene is tied onto the stem on either side of the area. Summer 2001 21 BARBARA SELEMON plants are harvested at any time from five months to two years following treatment, depending upon species. Barbara Selemon has been Plant Propagator for the Center for Urban Horticulture /Washington Park Arboretum for 16 years, specializing in the propagation of native plants for restoration as well as woody ornamentals. Mad rone Rooting Using Biotechnology 1 f ave Magnolia’s Madrones, a local commu- /^yV nity organization, funded a two-year research project for CUH researchers Dr. H.D. (Toby) Bradshaw and Barbara Selemon to test the ability of Agrobacteria rhizogenes, a soil bacteria, to induce roots on Arbutus menziesii, the Pacific madrone. Using seedlings grown from 20 trees found on the University of Washington campus, in the Washington Park Arboretum and in Hamlin Air layering of an Park, Shoreline, Washington, several inoculations Arbutus menziesii , . „ „ were made along young, growing stems of Pacific (Pacific madrone) seedling. s 7 * * Madrones. Agrobacteria rhizogenes causes swelling and tumors to occur when transfer of DNA is made to the injected plant tissue. It can also cause roots to occur adventi- tiously at the site of injection as a result of formerly unresponsive genes being sensitive to auxin, the plant hormone necessary for root initiation and development. This technique is a form of plant air layering using a biotechnological agent. Inoculations were made from September 1999 through September 2000 using three different strains of Agrobacteria rhizogenes obtained from a lab at Oregon State University. Many of the inoculations resulted in swelling of stem tissue, and some grew on to significant tumor size. Once root nodules were visible on stem tissues, the stems were wrapped with a moistened handful of peat moss and covered with plastic wrap. Five individual plants responded by making roots, and one plant made a significant enough root system to be severed from the mother plant and grown on as a new plant. Although few plants produced roots or became layered plants, this research work verified that Arbutus menziesii can be rooted using a biotechnological, air layering procedure. A review of the results suggests that further investigation into the type and virility of the Agrobacteria used may show that one particular strain outper- forms others. This method of propagating Arbutus menziesii using Agrobacterium rhizogenes to induce adventitious roots has not proven to be an efficient method for widespread use, but it could prove useful in the reproduction of rare and unusual plants that are difficult to root by conventional means. 22 Washington Park Arboretum Bulletin mm IN A GARDEN LIBRARY A True Treasure Trove By Brian Thompson ou may have barely noticed one of the highlights of this Northwest Flower & Garden Show as you ascended the escalators of the Convention and Trade Center to the glories waiting above. Along the walls and tucked in amongst the wall nooks of the second level was a collection of botanical art from the Royal Horticultural Society’s Lindley Library, traveling to this country from its home in London for the first time ever. This exhibition treated the viewer to visual pleasures equal to anything to be found upstairs, while gently imparting some of the history of botany and the techniques of its art. By bringing this display to Seattle, underwriter Darrell Allen gave a splendid gift to his fellow devotees of botan- ical books and won many converts. Now, it may seem rather cruel of me to be telling you this, months after the exhibit’s closing. Certainly it was best to see the The gooseberry, Ribes uva-crispa Crompton’s Sheba Queen,’ by Augusta Innes Withers originals, but faithful copies of most of these pieces can be found in Treasures of the Royal Horticultural Society: 350 Yeats of Botanical Illustration. This excellent publication, an exhibi- tion in its own right, is available for viewing at the Elisabeth C. Miller Library at the Center for Urban Horticulture. Published in 1994, Treasures represents part of the Society’s efforts to publicize its immense holdings of some 18,000 botan- ical drawings. Selected are seventy plates that date from the 1630s to the present and span the breadth of subjects, sources, styles, artistic methods and practices found in this previously little-known collection. From the glowing reds and golds of 17th century tulip cultivars, you can turn a few pages to find the same intense colors in a single Patrotia persica leaf painted in 1987. Enjoy the subtle beauty of a South African Protea repens painted in situ in 1838, or the 3/ plant genie