Albert Francis Blakeslee.

Trees in winter; their study, planting, care and identification online

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the borers with a sharp pocket knife. A flexible wire or a
common knitting needle may be used where the insect is located
far into the wood.

The larva of the Leopard Moth sometimes called the Imported
Elm-tree-borer, is one of the most destructive shade tree pests,
xlround New York, Boston and other cities along the north-
eastern coast it is becoming very troublesome. Its habits are
somewhat different from other borers in that it attacks the smaller

Fig. 94. Trees injured by the Leopard Moth or
the Imported Elm Borer.

branches at the top of the tree, where its presence is not usually
detected until the affected branches have l)een killed. The infested

area of a tree gradually extends downward until the




branches and even the trunk become affected. Tt borer often
completely girdles the branch and consequently that part of the
branch beyond the injury soon dies. Trees affected with leopard
moth borers are strikingly characteristic by their dead branches
at the top of the tree. Most kinds of deciduous trees are subject
to the attack of this pest, but the AVhite or American Elm has
suffered most.


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Fig. 95. The Leopard Moth Larva in its burrow. (Natural size.)

The following paragraphs are copied from the authors' summary of
a valuable bulletin by Britton and Cromie*: —

*^'The moths appear about July first, the males being very
common around electric lights, and the females lay eggs singly or

*Britton, W. E. and Cromie,
Sta. Bui. 169, 1911.

G. A. The Leopard Moth. Conn. Agr. Exp.


in groups of two, three or four, in the crevices of the bark or near
the buds. The larvae, hatching in a few days, begin to tunnel
in the twigs, and by the end of the season are about one inch in
length. They leave the small branches and crawl over the bark to
enter larger ones, cutting large galleries into them and expelling
the frass through round holes, which they soon close with silk wel^s.
During October the borers go deeper into the wood, and remain
through the winter two inches or more beneath the bark. They
pupate in their burrows the second spring, and before the moth
emerges the pupa works itself partly out of the opening, and the
aduJt flies away, leaving the empty case protruding from the

"There are few natural checks, only one parasite being known in
this country and four in Europe. It is believed, however, that
certain birds, especially w^oodpeckers, prevent the spread of the
leopard moth in the open country. Many larvae are doubtless
killed by the breaking off of the branches, which in cities are
carted away and destroyed.

"Removing infested branches; injecting carbon disulphide
(bisulphide) into the burrows, and stopping the opening; probing
with hooked wire for the larva ; are some of the methods of control.

"Planting species of trees not badly infested, like Oaks, Honey
Locusts and Sycamore, and especially those kinds that do not
grow very large, and have a smooth bark; placing trees further
apart, so that the larvae cannot easily crawl from one to the
other; and keeping the trees well nourished and vigorous, are the
chief preventive measures.'^


The reader will understand by this time that there must be two
distinct types of insecticides: stomach poisons and contact insecti-
cides. There are a great many belonging to each class. A large
number of them are superfluous, and to avoid confusion, only
those that are necessary and in common use are discussed here.

Stomach Poisons — The stomach poisons are those that kill
by being eaten, and are used for the control of insects that chew
their food. The most common stomach poisons are arsenate of
lead and Pa^is green. The latter sometimes causes injury to the
foliage unless used in combination with lime. It is generally used
in the following proportion:

Paris green 1 pound

Fresh stone lime 1 pound

Water 100 gallons

The Paris green should be mixed first in a small quantity of
water to form a thin paste. The lime also should be slaked in a
small quantity of water. Both materials may then be strained
into the spray tank and the required amount of water added.

Arsenate of lead, on account of its safeness, its sticking qualities,
and its general efficiency, has become the standard insecticide for
insects that chew their food. It may be made up at home, but
generally it is better to buy it ready prepared. It comes in either
paste or powder form. Most people prefer to buy the paste.
To prevent it from drying out, the paste should be kept covered
with water. It is generally used in the following proportion:

Arsenate of lead paste 6 to 10 gallons

Water 100 gallons

The paste should be mixed up with about two quarts of water
and then strained into the tank. Some insects are harder to kill
than others and should receive the maximum amount. Most
forms, however, are readily killed by using six pounds to one
hundred gallons.


Contact Insecticides — Insects that obtain their food by piercing
the epidermis and sucking the juices from the plant tissue, must
be killed by contact and the preparations used for the purpose
are called contact insecticides. Such preparations are usually
caustic in character and kill by irritation or by clogging the
breathing pores of the insect.

Common hard soap at the rate of one pound to six gallons of
water, is commonly used for plant lice. Whale-oil soap which
comes in paste form, is usually preferred for this purpose and is
used in the proportion of one pound to five gallons of water. It
is also used to some extent as a dormant spray for scale insects.
For this purpose it is used in the following proportion :

Whale-oil soap 2 pounds

AVater 1 gallon

Either kind of soap is more easily dissolved in hot water.

This preparation is too expensive to be used where there are
many trees to be sprayed, but when only one or two trees or a
few bushes are affected with scale insects, it is a convenient remedy
and is not so disagreeable to apply as some of the other prepara-

Kerosene emulsion is probably the best remedy for the control
of sucking-insects when the spraying must be done while the tree is
in foliage. A stock solution may be made up and used when
required and at any strength:

Kerosene 2 gallons

Hard soap }^ pound

Hot water 1 gallon

Cut the soap into thin slices, dissolve in the hot water, remove
from the fire and pour it into the kerosene while hot. Churn
thoroughly, or pump into itself with a force pump, until a creamy
emulsion is formed, which will mix readily with cold water. For
use on foliage, dilute at the rate of one to twelve. Some plants
with tender foliage require a weaker solution. For use on dormant
trees, dilute at the rate of one to three.

Tobacco decoction, made by steeping one pound of tobacco stems
or waste in two gallons of water, is a safe remedy for plant lice
on tender-foliaged plants.


The lime-sulphur wash is the standard remedy for the control of
scale insects on fruit trees. It may be made up at home, but it
is disagreeable and exacting work. It may be purchased in con-
sentrated form at from twenty to thirty cents per gallon and
is ready for spraying after diluting it with eight parts of water.
In this proportion it is used only while the trees are dormant. It
has extremely caustic properties and corrodes and discolors every-
thing with which it comes in contact. For this reason it should
not be used in proximity to painted buildings.

Miscible or ''soluUe' oils of which there are many brands on
the market, are useful and convenient preparations for the control
of scale insects. Compared with the lime sulphur-wash, they are
less corrosive, not so disagreeable to handle, and may be safely
used about buildings. They may be purchased at thirty cents to
one dollar per gallon, depending upon the quantity required. They
should be diluted with water in the proportion of one to fifteen
and should be used only during the dormant season. The con-
tainer should be shaken well before drawing off the oil. A few
drops of oil in a glass of water should produce a milky solution.
If the oil does not mix readily with water as indicated by this test,
it should not be used.

Carbon bisulphide is a heavy volatile liquid and is sometimes
used for the control of borers affecting the trunk, and of other
insects affecting the roots of trees. It readily evaporates when
exposed to the air. The fumes are poisonous and very inflamable.
A teaspoonful poured into the burrow of a wood boring insect, and
the opening stopped up with wax, will usually kill the pest. The
fumes being heavier than air, settle to the lower places and it is
well, therefore, to get the chemical into the top of the burrow. If
a tree trunk is badly infested it is sometimes advisable to arrange
an oil-cloth jacket around the trunk, tying it tightly above and
below the affected area. A saturated sponge holding about a cup-
ful of the liquid may be hung beneath the jacket and at the upper
part of the trunk. The fumes will penetrate into all crevices, and
within twenty-four hours the inclosed insects will be suffocated.


The use of fungicides is to kill fungus spores and to prevent
their access into the tissues of the plant. The standard fungicide
is Bordeaux mixture which may be made up as follows :


r Copper sulphate 8 pounds

^ \ Water 50 gallons

r Fresh stone lime 8 pounds

^ ^ Water 50 gallons

The copper sulphate may be dissolved either by the use of hot
water or by suspending it in a burlap sack at the top of a barrel,
of cold water. The lime should be slowly slaked, using a little
water at a time. When both solutions, a and h, are ready, they
should be poured simultaneously into the spray tank. When
large quantities are required it is customary to make up stock
solutions of copper s-ulphate and of lime, using two pounds of
each to a gallon of water. To make a hundred gallons of Bordeaux
mixture from these stock solutions it will be necessary simply to
measure out four gallons of each, dilute each with 46 gallons of
water (50 — 4=46), and strain into the spray tank.

AVhen a tree needs to be sprayed for some leaf-eating insect
as well as for some disease, six to ten pounds of arsenate of lead
may be added to every hundred gallons of Bordeaux mixture.
There are many brands of prepared Bordeaux mixture on the
market and some of them contain arsenic, either in the form of
arsenate of lead or Paris green. Pyrox and Bordeaux-lead are
common examples of such preparations. They are convenient
remedies and are very efficient, but cost more than the home-made

The commercial lime-sulphur wash Avhich has been discussed
under the heading of Insecticides, is also a good fungicide. When
used on Peach trees in the dormant condition, it may be depended
upon to kill scale insects and at the same time to control the
disease known as leaf-curl. It is also being recommended as a
substitute for Bordeaux mixture for spraying during the summer.
For spraying foliage, however, it should be diluted at the rate of
two gallons of the wash to one hundred gallons of water.


Most people fail to spray for the reason that they believe it to
be a difficult and exacting operation. Those who have had experi-
ence have gained confidence and now regard the operation as a
necessary item in their yearly routine. There are many ]-)rofossional


sprayers going around the country soliciting contracts for this
kind of work. Most of them are reliable^ yet there are some who
do not know the first principles of spraying and who have not
the proper equipment for the kind of work they undertake. When
reliable people may be engaged to do the work at the proper time,
it often would be advisable for the property-holder to have his
spraying done by contract. The property-holder, even though he
should not do his own spraying, should know something about the
subject so that he may know whether his work is being properly

AVhen spraying with arsenate of lead for the control of insects-
that chew their food, the spray should be applied until it commences
to drip from the foliage. Even though the foliage is not completely
covered, the insects, if they continue to eat, are sure to find some
poison. In the spraying for sucking-insects, on the other hand,
greater care must be exercised, for the spray actually must touch
the insect. In the application of fungicides, also, the whole
surface of the leaves must be covered to prevent the access of the
disease spores.

It is always desirable to spray with the wind. To do this it
is necessary to make a second application after the direction of
the wind has changed. With nozzles that make a fine spray,
it is impossible to spray against even the lightest breeze. It
sometimes happens that the work must be finished at one time
and it is possible to do so by selecting a still day and by using a
nozzle of the Bordeaux type that will produce a coarse spray. A
coarse spray will carry farther, but is more wasteful of material.

Spraying Machinery — For the private owner who has only a
few trees to spray, a barrel outfit operated by hand and costing
about twenty to twenty-five dollars, will answer the purpose. By
the use of extension ladders, extension rods, and long leads of
hose, it is possible to spray the tallest trees. Barrel outfits
mounted on two-wheel trucks may be purchased at a small addi-
tional cost and are very handy on small places. The small bucket
and knap-sack outfits are useful for bushes and young trees, but
are unsuited to spraying mature trees.

On large estates a power outfit of some kind will be found
very useful. When fine nozzles are used, a three horse-power
gasoline outfit may supply as many as six leads of hose. Such an




outfit will supply sufficient pressure for the spraying of the tallest
trees. 'Where it is desirable to reach the top of tall trees without

Fig. 96. Spraying- a large Elm Tree using a hand pump and two

long leads of hose. A very satisfactory outfit where there is danger

of disfiguring buildings and where a high-pressure outfit cannot be
used conveniently.


climbing, a more powerful outfit will be necessary. A ten horse-
power outfit will do the work and is very suitable for towns and
cities. Most municipalities have many trees in the open that may
be sprayed from the ground without fear of disfiguring buildings.
Spraying in this way is decidedly less expensive and less dangerous,
than where it is necessary to climb the trees. A powerful outfit












"^ ^iS^^^^I^I





Fig-. 97. The use of a high pressure pump in spraying taU trees.

may be used for both purposes. When wanted for working in the
vicinity of buildings, it may be adapted simply by changing the

Nozzles vary greatly in structure and adaptability. When spray-
ing at close range a nozzle that will make a fine mist or "fog" is



desirable. Those of the disc type are best suited to the purpose.
AVhen it is required to throw a stream high into the air a nozzle
of either the ^'Long Distance" or the Bordeaux type will be found
most useful. The "Long Distance" nozzle may be acQusted so

Fig. 98 An inexpensive
Spraying- Outfit for small
trees and shrubs.

Fig. 99. The Bordeaux Nozzle
commonly used in spraying
shade trees. It may be adjusted
to trow either a straight stream
or a fan-shaped spray,

as to regulate the size of the stream. The Bordeaux type (fig. 99)
may be regulated so as to produce either a straight stream or a
fan-shaped spray.

To avoid troublesome "blow-outs" it is well to use long shank
couplings and two clamps on each section of the coupling.

Rubber hose of the best quality is necessary for high-pressure
worlv. The half -inch size is sufficient for close work^ but for long
distance work it is better to use a larger size. It should be strong
enough to stand a pressure of at least two hundred pounds, al-
though for close work it is seldom necessary to maintain a pressure
of more than one hundred and twenty-five pounds.

Most spraying outfits are supplied with mechanical agitators to
insure the discharge of the mixture at uniform strength. On hand
outfits they are usually attached to and operated with the handle
of the pump. Such agitators seldom furnish sufficient agitation,
especially when there is only one nozzle in operation and the
handle is necessarily moving slowly. For the spraying of aresnate
of lead that quickly settles, it is safer to use an old garden hoe
with which the man who operates the pump may keep the mixture


thoroughly agitated. The best power outfits are supplied with
propellor agitators. These consist of shafts on which are fixed
two or three propellers like those used on small boats.


Before considering the individual trees in detail it seems de-
sirable to give a general discussion of the different terms used as
headings in the description of the species.

Name — A common English name heads the description of
each tree and this name is used throughout the book as the
designation of a particular species. The same form may be known
in different localities by several entirely different common names.
Thus the Tupelo in some places is called only Pepperidge, in
others, Sour Gum or Black Gum. After consultation with the
literature the name Tupelo was chosen as being somewhat more
desirable for the whole of New England than the other names
given in smaller type as synonyms. Often several common names
may be in about equally frequent use. There is in general, only
one scientific name at present sanctioned by botanical authorities
and this is placed first, followed by the Latin synonyms in italics.

Habit — By the word habit, we denote the general appearance
of a tree seen as a whole. A tree strictly speaking is generally
considered as a woody growth having an undivided trunk at the
base and rising to at least twice the height of a man. A shrub
on the other hand is low-growing and may branch from the very
base. No hard and fast line, however, can be drawn between a
tree and a shrub. Many trees at the limit of their range or
under unfavorable conditions are reduced to the form and dimen-
sions of a shrub and some forms growing as shrubs in New England
become trees in states outside this group. A young tree sometimes
resembles a shrub, but is more ra])id in growth and generally does
not bear fruit until it has reached a considerable size. Of the
forms on the borderline between trees and shrubs only those have
been treated that have demanded recognition on account of their
commonness or their relationship with other forms.


Two general habit types are recognized — the spreading and the
erect — often termed deliquescent and excurrent respectively. The
former is well represented by the Apple (p. 353) and White Elm
(p. 327) and the latter by the Evergreens and those of the Poplars
that form narrow conical heads (p. 261-263). By its more erect
habit of growth the Sweet Cherry (p. 369) is readily distinguished
from the Sour Cherry (p. 371) and in like manner the Pear
(p. 351) from the Apple (p. 353). It is these habit differences
that form the most ready means of separating the contrasted
trees just mentioned which may closely resemble each other in twig
characters. The angle which the branches make with the trunk
is frequently a diagnostic character of considerable value. For
example, the ascending and gracefully outward curving limbs of
the American White Elm (p. 327) stand in contrast with the
sharply divergent limbs of the English Elm (p. 325). Likewise
the horizontal branches of the Tupelo (p. 421) and the strongly
pendant low^r limbs of the Swamp White Oak (p. 305) are char-
acteristic of these species. The relative thickness of the branchlets
contrasted in the Sweet Cherry (p. 369) and the Black Birch
(p. 281) and the arrangement of the branchlets whether opposite
or alternate and whether erect or drooping, may further be men-
tioned as habit characters.

As one becomes more familiar with trees in their winter aspect,
the number that cannot be recognized at a distance becomes greatly
diminished. We come to know trees by hardly definable traits,
much as we recognize our friends at a distance by some peculiarity
of form or gait. Watching the trees from a car window is a
great help in acquiring this familiarity with the habit characters.
The method of branching and other features included in the habit
do not furnish such precise marks as do the twigs, and cannot
therefore be of much value in a descriptive key. In fact the
habit varies considerably among individual trees of the same
species, no two trees having exactly the same method of branching.
Moreover trees grown in woods in company with other trees are
prevented by lateral shading from developing their normal form
and produce tall trunks with but little branching. On the other
hand trees apart from other trees have usually been planted for


ornament or have originally grown in woods but have been left
isolated by the cutting down of their neighbors. In the latter
case the habit will be more or less that of a forest-grown tree
dependent upon the age at which the conditions of light and
shade were altered (see lower habit picture p. 329). In the
former case the top of the young tree may have been cut in the
process of transplanting causing an increased branching at the
point of cutting and the lower limbs may have been trimmed off,
giving a greater show of trunk. These mutilations, however, have
less influence upon the outline of the head or crown than might
be imagined since the tree is generally able to accommodate itself
to such accidents as those mentioned and express its individuality
despite them. The age of the tree is also an important factor
in the outline, young specimens being in general narrower and
more conical than in later life while those in old age may have
lost shape through ice storms, high winds and the attacks of fungi.

So far as possible the photographs may have been taken from
mature specimens growing in the open and only those have been
chosen which have been considered to present an appearance typical
of the species. They will help one to form a mental picture of
those generalized features of a tree in the landscape which may
be recognized at a distance, but w^hich are difficult of analysis.

Bark — Although it is upon the appearance of the bark more
than upon any other character that the woodsman depends in his
recognition of timber trees, the bark shares with the habit the
misfortune of being difficult of precise description. A study of
the photographs, however, in connection Avith the description of
the color and texture will enable one to recognize a large propor-
tion of our trees by the appearance of the bark alone. They
have been taken from mature trees of moderate size which have
developed the characteristic sculpturing of the bark rather than
from those of larger size which are less frequently seen. A tape
measure surrounding the trunk or in some instances a penknife
stuck into the bark may serve to give an idea of the relative size
of the markings on the trunk. The heading "Bark" is used
throughout the descriptions in reference to the trunk and larger
limbs and not to the twigs which are described under another


The color of the outer bark is an important mark of distinction
and is the chief means of separating the different species of the
Birches (p. 281-291). The color and taste of the inner layers
of the bark are in some cases also characteristic. The Black
Oak for example is best distinguished from other Oaks by the
yellow and intensely bitter inner bark. Similarly, the Black Birch,
the Sassafras and the genus Prunus including the Cherries have
b'arks with characteristic flavors. The swamp-loving Poison
Sumach (p. 395) is the only poisonous tree in New England so
that after this shrubby form is known there need be no fear of

Online LibraryAlbert Francis BlakesleeTrees in winter; their study, planting, care and identification → online text (page 13 of 31)