; UNITED STATES

u.s

4*M|

. . . 3ul. 37.

H.

Cox

Septeraber 18, 1915

I

UNITED STATES DEPARTMENT OF AGRICULTURE

FARMERS'
BULLETIN

WASHINGTON, D. C. 687 SEPTEMBER 18, 1915

Contribution from the Bureau of Plant Industry, Wm. A. Taylor, Chief.

ERADICATION OF FERNS FROM PASTURE LANDS
IN THE EASTERN UNITED STATES.

By H. R. Cox,

Agriculturist, Office of Farm Management.

KINDS OF FERNS THAT ARE WEEDS AND AREAS INFESTED.1

There are nearly 7,500 recognized species of ferns in the world, of
which number over 200 are known to be native to the United States.
A few species have become weed pests in this country, and it is to a
discussion of the control of these weedy ferns that this bulletin is
devoted.

The parts of the United States in which ferns are bad weeds are,
principally, (1) the hill country of the Northeastern States and the
higher portions of the Appalachian Mountain region as far south as
Georgia, and (2) the Pacific coast country west of the Cascade
Mountains. In the former region, which is the area covered by this
bulletin, the principal weedy ferns are the hay-scented fern (Denn-
8ta«ltia punctilobula) and the brake (Pteris aquilina, formerly known
as Pteridium aquilinum). Both kinds are sometimes called brakes,
although tliis term is properly applied only to tho latter species. In
Ihe Pacific coast section the brake is the most common weedy fern.

Several other species in the eastern region are sometimes annoying,
but they occur largely in low and moist places and do not give much
trouble on good pasture land. They are principally the cinnamon
fern (Osmunda cinnamomea), the marsh fern (Orihopteris thelypteris),
and the sensitive fern (Onoclea sensibilis).

i The writer is indebted to Mr. J. S. Cotton, of the Office of Farm Management, for valuable suggestions
in making the experiments described in this bulletin.

N ( > IF..— This bulletin will be of interest to farmers in the hill country of the Northeastern States and the
higher poriions of I lie. Appalachian Mountain region farther south.
2219°— Bull. 687—15

487<y

FARMERS' BULLETIN 687.

SCOPE OF THIS BULLETIN.

Tin's publication deals only with fern eradication in the Eastern
States. Although the experiments here recorded were made with
the hav-scented fern, there is every reason to believe that the methods
found useful against this species would be equally applicable to the
brake. It should be understood, however, that the fern referred to
in the following pages is the hay-scented fern.

HABITS OF GROWTH OF THE WEEDY FERNS.

THE HAY-SCENTED FERN.

The hay-scented fern (fig. 1) has a perennial,
very slender rootstock one-eighth to three-six-
teenths of an inch in diameter, extensively
creeping below ground parallel to the surface.
From the rootstocks arise at short intervals
the fronds, or leaves, of the plant. These
fronds are 1 to 3 feet high and 5 to 9 inches
wide when mature. The fruit dots occurring
on the margin of the leaf bear the spores which
arc comparable to the seeds of seed-bearing
plants.

This kind of fern grows in patches or clumps
(fig. 2) , the surfaces of which are raised above
the rest of the land and are soft and spongy,
consisting of an accumulation of dead fern
and forest leaves. In these clumps the fern
leaves grow so thickly that young grass has 110
opportunity to work in. Even if grass could
get a start in the clumps, it would be smoth-
ered out when the fern leaves fall over and die
on the coining of cold weather.

The hay-scented fern is rather particular as
to location. It thrives in places partially pro-
tected from the sun's rays, such as northern, eastern, and western
slopes, or in areas close to stone walls or trees. It is noteworthy
that this fern is not found in places that are much trodden. Either
the plants have been driven out by the trampling of animals or the
soil is so compact that tin* fern can not get a start.

THE BRAKE.

The brake (fig. 3) has underground parts similar to those of the
hay-scented fern, but the rootstocks are more stout and woody and
creep longer distances below the soil surface. The brake also has the
same methods of reproduction as the hay-scented fern. The plant

Fro. 1.-— The bay-waited

fern.

ERADICATION OF FERNS FROM PASTURE LANDS. ' ' ' '•#

varies much in size; in the Eastern States it is 1 to 3 feet high, but on
the Pacific coast it attains a height of 6 to 8 feet. The leaf blades are
triangular and umbrella-like, 1 to 4 feet broad, and long and more or
less three parted, the larger branches usually twice divided. At
maturity the fruiting leaves have a continuous edging of spore cases,
which shed the light-brown spores in great quantities.

In the Eastern States the brake is distributed somewhat more gen-
erally than the hay-scented fern, not being confined so exclusively to

5$S

FIG. 2.— A pasture in southern New York with a characteristic growth of hay-scented ferns.

the hill and mountain country. From its habit of being widely creep-
ing, the brake does not occur in dense, well-defined patches, like the
hay-scented fern (fig. 4) .

CONTROL OF FERNS IN THE EASTERN STATES.

As the grazing of live stock is a prominent feature in the farming
of the eastern region in which ferns are weeds, and as the area of avail-
able pasturage has been curtailed by the presence of the ferns, thesQ
weeds are looked upon as a serious pest. Moreover, since these lands
for the most part are so steep and rocky as to prohibit cultivation, and
since the ferns, unlike many other pasture weeds, can not be reduced
in number by increasing the vigor and thickening the stand of the
pasture grasses, a real problem in weed control is presented.

FARMERS' BULLETIN 687.

METHODS ALREADY IN USE.

The methods that have been adopted for eradicating ferns in the
Eastern States arc cutting or mowing, salting live stock, and culti-

vation.

CUTTING OR MOWING.

In 1557 Thomas Tusser wrote his "Five Hundred Pointes of Good
Husbandrie," in which he said:

In June and in August, as well doth appeere,
Is best to mowo Brakes of all times of the Yeere.

In 1911 a representative of the
United States Department of Agri-
culture found a farmer in Delaware
County, N. Y., who was following
the identical method advised by
Tusser and had greatly reduced the
number of ferns in his pastures.
(See fig. 5.) This farmer, Mr. W. J.
Thomson, has found that attacking
them twice a year greatly reduces
the number of ferns, and that if the
method is followed for two years
in succession most of them dis-
appear.

It is best to make the cuttings
just previous to the time when the
ferns mature their spores. This
not only prevents propagation by
means of spores but greatly weak-
ens the rootstocks, which are at
their most susceptible stage just
previous to sporing. As the spores
mature during the latter part of
June in Delaware County, the
proper time to make the first cut-
ting in that region is about the
middle of that month. New leaves spring up immediately, so that
one more cutting must be made* that season to prevent sporing. This
second cutting should be made about the middle of August. It is
highly important to observe the precaution that if either of the cut-
tings is put off until after the spores mature, the plants should not
be disturbed during the remainder of that season, since mowing the
ferns after the spores ripen seems to scatter the spores a great deal
more than when the plants remain undisturbed.

The work of cutting must usually be done by hand (fig. 6), as the
land is generally too rough to admit of the use of a mower. In a

FIG. 3.— The brake.

ERADICATION OF FERNS FROM PASTURE

pasture with an average quantity of fern, one man with a scythe can
cover about 2J acres in a day. The leafstalks are tender and are
easily cut with a scythe.

The writer has found a number of farmers in the mountain-pasture
district of North Carolina who have successfully used this method of
eradicating ferns. The plan seems to be generally accepted as the
best in that region.

Burning after cutting.— Mr. Thomson has found that burning over
the fern patches after cutting serves as a further check to the pest.

FIG. 4.— A field infested with brakes, near Tacoma, Wash.

After the mowed fern leaves have become dry, fire is started on the
windward side of the patch. Not all patches will burn completely,
a;s there are varying quantities of combustible material in the areas.
Where a fierce fire has passed over a patch the fern rootstocks are
undoubtedly injured to a considerable extent.

SALTING LIVE STOCK IN FERN PATCHES.

Where ferns occupy very small areas on a farm certain methods
may be used that would not be economical on a thickly infested piece,
of land . One of these methods is salting live stock in t ho fern patches.
Dry salt is scattered on the plants when they arc moist with rain or

.6.:"-': :..: -''''•'

BULLETIN 687.

dew. The stock eat and trample the plants in their effort to get the
salt. This plan has been successful on at least one farm near Delhi,
N. Y. Since the saltings must be rather frequent, the areas treated
should be those that are easily accessible.

CULTIVATION.

There is no doubt that cultivation destroys ferns. The difficult
is that the steep and rocky character of the fern-infested land does
not permit effective cultivation except on limited areas. Cultivation
has been tried on Mr. Thomson's farm with indifferent success.
When a piece of pasture was plowed up and put into small grain, fol-
lowed by seeding to grass, the fern worked in again, so that it is now

FIG. 5.— General view in southern New York, showing land in the foreground on which hay-scented ferns
have been eradicated by cutting.

as thick as formerly. Another piece of pasture land was well culti-j
vated in potatoes and afterward seeded to grass. In this piece the
fern was slower in working back, but later a fairly good stand of tho
weed was found. If the cultivation could have been continued for
several years, permanent eradication of the fern might have been
expected, but the character of the land prevented this treatment.

EXPERIMENTS IN FERN ERADICATION.

Having learned the value of the various methods already in use in
controlling ferns, the question arose whether there were anv other
methods that might be more satisfactorily employed. Spraying with

ERADICATION OF FERNS FROM PASTURE

plant poisons suggested itself as the most promising. Accordingly,
experiments were planned in cooperation with Mr. Thomson to com-
pare the value of spraying with cutting, as well as to learn something
about the best way of getting a stand of grass and clover on the in-
fested areas. These experiments covered a period of two years, 1912
and 1913.

EXPERIMENTS IN 1912.

The tests were made in two series. Series 1 consisted of spraying
to kill the ferns, accompanied by seeding, liming, and fertilizing to
encourage a stand of grass. All plats were sprayed twice except one,
which was sprayed four times. Series 2 consisted of cutting, also
accompanied by seeding, liming, and fertilizing. Each plat was cut

FIG. 6. — Cutting ferns with a scythe on a hillside.

twice. The two sprayings and two cuttings on the various plats were
made about the middle of June and August, just preceding sporing
time.

Sprayed series. — The number of sprayed plats was four, all being
uniformly and fairly well set to ferns. The materials used were
solutions of common salt, iron sulphate, and arsenitc of soda, and in
order to make the treatments comparable as to cost the quantities
applied to the various plats were of equal value. The sprayer used
was a hand bucket pump, which produced a fairly mistlike spray.
The entire surface of the plat was treated, the grass as well as the
ferns. One-half of each plat was limed and fertilized in June at the
rate per acre of 300 pounds of acid phosphate, 150 pounds of muriate
of potash, and 2,000 pounds of hydrated lime. The entire surface of

-S.- "V- »•'•"' FARMERS' BULLETIN 687.

all the plats was seeded to a pasture mixture of grass and clover in
August.

. Cut series. — The number of cut plats was two. They were both
treated alike as to cutting, but one of them was limed and fertilized
in June and seeded in August, while the other was merely seeded in
August.

EXPERIMENTS OP 1913.

It was the intention to duplicate the treatment of 1912 on all the
plats. In the spring of 1913, however, it was evident that the- re-
sults of spraying on the plats treated with salt and arseiiite of soda
in 1912 had been so effective that there was not much foni left on
v liich to experiment. Accordingly, two new plats were laid out in
1913 to test the relative merits of these two materials. The quantities
used were less, but were equal as to cost, as before. Each plat was
sprayed twice.

In addition to these two plats, two small areas of the 1912 sprayed
plats were sprayed with the same solutions described above to note
their effect on the young seeding of grass and clover.

There were no cutting plats in 1913, as there were numerous places
in the fields where the fern had been cut one year and also two years
in succession. The cut plats of 1912 were untouched in 1913 in
order to note the fighting qualities of the fern in the presence of the
new seeding of grass and clover.

CONCLUSIONS FROM EXPERIMENTS AND OBSERVATIONS WITH FERNS.

CUTTING.

Cutting ordinarily is a cheaper method of handling ferns than spray-
ing. With ferns at an average degree of thickness in a pasture a man
ought to cover about 2\ acres a day. With labor at $1.50 the cost
of cutting fern is about 60 cents an acre for each cutting, as com-j
pared with spraying with salt at about $1.05.

A further advantage of cutrtmg is that it is less complicated than
spraying and requires only the use of a tool with which all farmers
are thoroughly familiar.

Still another advantage is that seeding to grass and clover can be
made as soon after the first cutting as is desired. After the original
stand of ferns is cut down, the subsequent growth is seldom so thick
as to prevent young grass working in. The seeding can be done
the. same year that the work of eradication is started, so that bv the
following year a good growth of young grass and clover may bo
expected, which in itself contributes to the reduction of the number
of ferns.

ERADICATION OF FERNS FROM PASTURE LANDS.

SPRAYING.

There is no doubt, that salt is the host material for a spray solution
against ferns. (Sec fig. 7.) The iron sulphate was ineffective.
Arsenite of soda was effective, but its use involved some risk on
account of its poisonous character to man and animals; furthermore,
it is rather difficult to obtain except in the larger centers. Salt is
very effective, is easily obtainable, and probably exerts an aftereffect
favorable to grass. It is also relished by live stock, thus contribut-
ing to the destruction of ferns treated with it in pastures to which
stock have access.

FIG. 7. — Fields in southeastern New York where the experiments in fern eradication were made. In the
immediate foreground is the plat sprayed with salt solution, which accomplished the destruction of
nearly all the ferns in one season.

The quantity of salt required to the acre depends, of course, on
the thickness of the fern. The smallest amount used in the experi-
ments was 600 pounds to the acre, and this was considerably more
than was needed, even though the entire surface of the plats, both
the fern and the grass, was treated. As the ferns seldom occupy morn
than one- third the surface of a pasture, 200 pounds to the acre is
usually ample. In these experiments salt was used in almost a satu-
rated solution, that is, 1 pound to about 1J quarts of water. If
desirable, a more dilute solution could be used.

10

The cost of spraying varies under different conditions and is here
only estimated. The difficulty of hauling water up steep slopes is
sometimes so great as to make spraying almost prohibitive. After
the materials are hauled to the field, the work of spraying proceeds
faster than cutting. With ferns of an average degree of thickness
a man with a knapsack sprayer ought to cover about 5 acres a day.
Assuming that 150 pounds of salt are used to the acre at a cost of
one-half cent a pound and that 5 acres are covered in a day with
labor worth $1.50, the cost of spraying with salt is $1.05 per acre for
each application, not including the cost of hauling the materials. As
the first spraying is the most expensive in labor and materials, this
treatment may cost a little more than the amount mentioned, while
the subsequent treatments will probably cost less.

One disadvantage of spraying is that it is a detriment to the growth
of young clover. This means that the measures for encouraging the
clover to work into the patches occupied by fern should be deferred
until after tlie last spraying has been made. It is probable that the
spray does not injure young grass to any great extent.

An advantage of spraying is that it may be employed in situations
that arc too stony for the efficient use of the scythe (fig. 8). There
arc also certain other situations where large spraying outfits may be
satisfactorily used. Spraying with a barrel pump on a low wagon can
sometimes be made more cheaply than with a knapsack outfit.

NUMBER OF TREATMENTS NECESSARY.

Two treatments a year, either spraying or cutting, seem to be
about as effective as four, and are to be recommended. Undoubtedly
the best time to treat the ferns is just previous to sporing, or about the
middle of June and the middle of August.

BURNING.

Following a treatment of either spraying or cutting, fire may be
started when, the vegetation on the surface of the patches is dry.
The burning not only kills the shoots that have recently started, but
probably affects the vitality of the rootstocks as well. The subse-
quent growth of young shoots is usually not as vigorous as when the
patches are not burned. The burning should be done, of course,
before seeding to grass and clover.

HOW LONG SHOULD THE MEASURES OF ERADICATION BE CONTINUED?

It is probably not practicable absolutely to eradicate ferns. After
they have been reduced to a minimum the specific methods of de-
struction may be discontinued, at least until the weeds again become
troublesome. The reduction of the number of ferns will give the
grass and clover ample opportunity to work in, and this in itself will
tend to hold the ferns in check.

EKADICATION OF FERNS FROM PASTURE LANDS.

GETTING A STAND OF GRASS ON THE FERN PATCHES.

11

After the fern has boon greatly reduced or entirely eradicated,
grass is very slow in working into the patches unless certain measures
are adopted. Of these measures, scattering grass and clover seed
over the patches is the most important one. The stand is better
and the growth more vigorous, especially in the case of clover, if lime
and fertilizer are applied in addition to the seed.

Seed may be sown either in the early spring or late summer. In
these tests the seed was applied at the latter period, that is, during

PIG. 8.— View of a pasture from which ferns have been eradicated, except amoni; rocks and close to the
1 stone fence, by cutting. This pasture presents conditions under which spraying with a salt solution may
I be the best method of eradication.

Lugust, with excellent results. If the seeding be done at this time
Ihe young grass seedlings are less injured, probably by the shading
Meet of the ferns, than if done in the early spring.

CONTROL OF FERNS IN THE WESTERN STATES.

The brake is fully as serious a weed pest on the Pacific, coast as are
.i of the fern species hi the East. A thorough investigation of the
fern problem of the Western States has not been made ad yet by the
Department of Agriculture. There is no doubt, however, that the
ferns of that region may be subdued by the same methods used m
the East, with certain modifications to meet local conditions, espe-
cially in 'the time of application of the treatments. Owing to the

.,

12

nature of the land and the kind of farming in vogue on the Pacific
coast there are several methods that can probably be used to advan-
tage in that region that can not be employed in the East.

SUMMARY.

Two kinds of ferns have become serious weed pests in the United
States, namely, the hay-scented fern and the brake. The two species
are troublesome in the hill country of the Northeastern States and
in the higher mountain country of the States farther south. On the
Pacific coast the brake is the principal weedy fern.

This bulletin deals with the fern problem of the Eastern States!;
Although the experiments here recorded were made with the liav-
scented fern, there is no doubt that the treatment found most effectiv
with that species would apply equally well to the brake. Both kiiK
are perennials, with running rootstocks which lie more or less parall<
to the soil surface.

In most parts of the East where the ferns are weeds the land is s
steep and rocky that cultivation is not practicable. It has bee
found that cutting off the tops close to the soil surface twice a ye;
for two years will kill out nearly all of the ferns. The best times to d
the cutting are just previous to sporing, or about the middle of Jun
and the middle of August in southern New York.

Experiments were made in 1912 and 1913 to test the effieacv
spraying as compared with cutting and to learn the best method
obtaining a stand of grass and clover on the fern-infested areas
The spray materials used were solutions of salt, arsenite of soda, an
iron sulphate. These materials were used in quantities of equal value

The results of these tests showed the following facts: Salt is tli
best spray material of the three. With ferns at an average degrt
of thickness on the land, 150 pounds of salt dissolved in 60 gallon
or more of water to the acre for each application are sufficient. T\\
sprayings a year are about as effective as four, and are to be recom
mended. Cutting is somewhat cheaper than spraying. Further
more, the cutting does not interfere with young clover and gn
coming in on the infested patches after the first treatment. Tl
method, therefore, is to be recommended in preference to spray in
in most situations. In some places the land is so stony as to inter-
fere with cutting, in which case spraying may be the best metho<
It was found that scattering seed on the patches where ferns ha
grown was the most important means of getting a stand of grass an
clover, and that liming and fertilizing in addition to the seeding wei
of considerable benefit.

WASHINGTON : (ioVKHN.MKNT 1'KlNTiyi:

Syracuse, Is. >
PAT. JAN. 21 ,1908

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