Albert Francis Blakeslee.

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

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a scanty supply of foliage should be severely cut back. The re-
moval of three-fourths of the top during the following winter would
tend to awaken new activities. When we consider that the new
growth and the development of the foliage and blossoms must come


Fig. 59. Heading-in neglected Apple Trees to render them more

easily sprayed and to facilitate the harvesting of the fruit,
practice in New England.

A common

from the energy stored up in the lower part of the tree and in the
roots, it is not surprising that there is sometimes a feeble growth.
By removing a part of the top, all of the stored-up energy is forced
into the remaining part with the result that the tree, during the
following season, carries fewer leaves, but these are of a better
color and appearance. A tree sometimes becomes constitutionally
unbalanced from the effects of an inadequate supply of food or water
or from the effects of insect attack, fungus disease, or mechanical
injury. A tree in this condition has not sufficient energy stored up



to put out the required foliage to properly nourish the tree and to
store up enough reserve food material for the following year's
growth. As a result the tree becomes weaker and weaker and,
unless it receives help, finally dies. A severe pruning, while dor-
mant, tends to throw the tree back into proper balance.

Except in serious cases, it is not necessary to completely dehorn
the tree, many weakened trees require only a severe general prun-
ing to put them into proper balance^ and with such it would be
unwise to spoil their shape by dehorning. Some ill-formed trees,
on the other hand, are improved in shape by a moderate heading-
in. Neglected apple trees for example, are being severely dehorned

Fig-. BO. Old Apple Trees one year after being "dehorned."

by many growers in New England and New York for the purpose
of reducing the height of the trees and of developing new heads
nearer the ground. In the most severe cases the whole top is
removed, leaving nothing but stubs from which sprouts readily de-
velop, and these when properly trained, form the new head. (See
figs. 59 and 60).

AYhen weakened trees are dehorned or severely pruned they
should be given good care in every respect. The breaking up of the
turf and the application of fertilizers in the spring and the supply-
ing of water during dry seasons, will go a long way toward reju-
venating old and weakened trees.

Taking Care of Recent Injuries — Fresh wounds are frequently
found on the trunk or main branches of trees. These are usually
the result of accident, of carelessness, or of wilful destruction. In
some cases trees become girdled from leaving wire labels attached,
from guy wires in construction work, or by mischievous boys. In



Fig 61 A good example of the use of zinc in covering a surface

r^h. h t''T.?f '^' ''"" *' ''""^ ^^°^"^^ ^° ^^^ f^^^hly cut edges
of the bark and It is applied in pieces that overlap like shingles on a



other cases the trees are injured by horses or passing vehicles.
Wounds made from any such causes may be easily and quickly
healed if treated before the wound has had a chance to dry out.
They should have their edges trimmed up with a sharp knife,
always cutting back to firm bark. The whole surface should then
be covered with grafting wax and bandaged with cloth. If done
in the early part of the summer a new bark will develop over the
whole surface. This method of healing is different from that
associated with old wounds.

Where a portion of the bark has been removed all around the
trunk, the trouble is more serious, but if the wound is not more than
three or four inches in width and if the injury occurred in the early
part of the summer when the cambium is active, the tree may be
saved by protecting the wound with wax as just described. If the
wound has become somewhat dried, or if it is a wide one, it will
be necessary to resort to bridge-grafting.

For "bridging" a wound it is necessary to smoothly cut back the
edges of the wound to sound bark and connect the two edges with
freshly-cut scions. The scions should be of the past season's growth

Fig-. 62. Bridge Grafting. A process used in healing over wounds
that extend clear around the trunk or a large branch.


and ma}^ be taken from the same tree or some other tree of the same
species. The scions shoiikl have their leaves removed, their ends
cut wedge-shaped, and slioidd be just long enough to extend under
the bark about an inch at each end. The whole wound, scions and
all, should be covered with soft grafting wax and cloth bandages.
The scions, when they become united to the bark at both ends, serve
to conduct the elaborated food material down to the lower part of
the tree. In time the wound will heal over completely. (See fig.

Wounds of the previous season, or those that have been allowed
to dry out, will require different treatment. A girdled tree, if not
treated soon after the accident, will die, but so long as there is a
strip of bark remaining there is hope for the tree. In such cases,
the edges of the wound should be cut back to living cambium and
the wound thoroughly sterilized with copper sulphate, one pound
to ten gallons of water. The whole wound, as soon as dry enough,
should be painted with ordinary white lead paint, or with coal tar,
and then covered with zinc. The zinc should be cut so that it will
fit exactly inside of the wound, and in this way allow the bark or
margin of the wound to heal over the edge of the zinc. The edge
of the zinc should be firmly nailed down, using large-headed nails
not more than an inch apart. The zinc may be painted any color
that will be inconspicuous. If the zinc should become broken so
that water may enter, it should be promptly removed and replaced
with whole strips.

Filling Cavities — Many trees whose trunks have been complete-
ly hollowed out, have been saved from breaking down by the use
of gement filling. Cement is used largely for support and acts
as a reinforcement. In order that there should be no further
decay the work must be carefully done. The accompanying illus-
tration, figure 63, shows the various stages in filling a knot-
hole cavity. Briefly stated the work consists in cleaning out
all the decayed material, sterilizing with copper sulphate so-
lution, and filling with concrete. The edges of the wound
should be trimmed back to living bark. Knot-hole wounds are
usually prepared by sawing off the projection or lip around the
wound. If the decayed area has not extended far enough to weaken
the tree, the cavity need not be filled. It should be cleaned and



Fig-. 63. Tree Surgery. Various stages in the treatment of knot-hole



sterilized^ however, and the opening covered with zinc as described,
for large wounds made by pruning.

In slender cavities where there is a small opening, it is necessary
to make some additional holes through the living bark and wood to
facilitate the work of cleaning (see fig. 64), and it is often neces-
sary to enlarge the opening to give more room for working. In
such cases it is also necessary to make up the cement mixture in
a semi-liquid form, so that it will flow into all crevices.








HH' '"J










■■ ^ii


Pig. 64, A well-
fiUed cavity showing
the three holes that
were made through
the Hving bark to fa-
cilitate the work of
cleaning out and af-
terward filled with





H^ i


Pig-. 65. This kind of cavity work
does not detract from the appear-
ance of the tree and is a permanent
improvement. Observe that the

cement is molded to form a convex

^ ^^

Pig. 66

. A poor




that th





and is badl


It als


over th

edge of

the bar!

preventing it




Very large openings will need to be bricked np to hold the con-
crete in position. The proportions used in making np concrete
varies, but most experts use one jDart cement, two parts sand, and
four parts crushed stone for the main filling. Just enough water
is added to make a mixture that will settle well into all crevices
without much tamping. The finishing is done with a stiffer mix-
ture made up of one part cement to two parts of fine sand and just
enough water to make a good mortar. Sometimes nails are partly
driven into the main filling to assist in holding the finishing ma-
terial in position until it has hardened.

The finishing of the surface is one of the most important feat-
ures of the work. The filling should be left with a convex surface
and the edge of the concrete should be beveled off so that it comes
jr«;t beneath the cambium layer or inner bark. If the finishing is
properly done the callous will form over the edge of the filling. In
long cavities that extend far up the trunk, it is customary to divide

Fig. 67. Cross-section of a filled cavity, showing the correct position
of the concrete in relation to the bark and cambium. B — bark; C —
cambium or inner bark; SW — sound wood; MF — main filling of concrete;
P — iron pipes for reinforcement; F.C. — finishing concrete.


the filling into two or more sections by cutting into it with a
knife in about the same way that sidewalk builders section off
their concrete walks. (See figs. 64 and 65). This precaution
obviates the irregular cracking of the concrete due to the swaying
of the tree by the wind. By reinforcing the concrete, also, with two
or more steel uprights, by numerous steel rods, or by iron pipes,
the danger from cracking the filling is greatly reduced. Even
though no cracks are made in the concrete there is likely to be a
crack between the wood and the filling, where water is likely to en-
ter. For this reason some prefer to cover the concrete with zinc,
tacking it down on a freshly-painted surface as previously de-

Bolting and Cliaining — Some trees with bad crotches, like the
Elm and Silver Maple, are very liable to split down, unless protect-
ed in some way. Any tree with a cavity in its tmnk, no matter how
small, is likely to split open, due to the freezing of the accum-
ulated water. Trees affected in this way, of course, should first
have their cavities filled and the water prevented from accumu-
lating. Any tree that shows a tendency to split should be sup-
ported by bolting or chaining. It is also well to preclude damage
by bracing all trees with bad crotches, even when there is no indi-
cation of splitting. A sudden storm often tears large branches
from the trees that are least suspected of being injured. When
the branch is completely severed there is no hope, and all that can

Fig-. 68. The result of improper methods
of supporting- a weak crotch.

be done is to trim up and dress the wound. If the branch is not
completely severed and if it may be readjusted without injuring the
connecting tissue, the chances are favorable for saving the limb.



There are many mistakes made in attempting to support a tree
prone to splitting. Sometimes more harm than good is done, and
frequently good trees are seriously injured by the good intentions

Fig-. 69. The proper method of inserting a bolt.

of the owner or the poor judgment of the so-called "tree-doctor."
The use of chains, wires, or iron bands around two or more branches
is sure to cause injury. When trees are supported in this way there
is no opportunity for expansion or growth without bringing much
pressure on the bark, and, as a result, the branches affected are
partially girdled and either killed or greatly weakened. (See fig.

When the branches are far apart, the best method of bracing is
in the use of bolts with a hook on one end and a large w^asher and

Fig-. 70. Method of bolting a tree possessing three or more main


nut on the other. These are inserted by boring a hole clear
through the branch and by counter sinking the washer and nut as
shown in figure 69. Two or more of the bolts may be inserted and
connected by wires or chains. The nuts soon become imbedded in
the wood and the result is a very efficient and inconspicuous method
of bracing.

AVhere the branches are near together, as is usually the case with
Elms and Silver Maples^ the bolt may be made long enough to
extend through both branches and threaded at both ends. The
nuts and washers in this case, also, may be countersunk. The
nearer the crotch the stronger should the bolt be to stand the great
strain during wind stonns. A one-inch bolt at a distance of three
or four feet from the crotch is sufficient except for the larger trees.
AVhen the bolting is done at a distance of four or more feet from
the crotch there is more or less swaying motion that tends to weaken
the bolt. For this reason, bolts connected by chains are preferable
to solid boItS; except at points very near the crotch. .




Trees are subject to a great many kinds of disease. Few diseases,
however, are so serious as to require treatment. Tree diseases are
caused mostly by parasitic fungi, which are low forms of vegetable
life that live upon and within the tissue of the host plants. The
most serious forms, from the shade-tree standpoint, are those caus-
ing the decay of the trunk and main branches. Since such forms
are not capable of entering the uninjured bark these troubles usually

Fig-. 71. A Red Oak tree injured
at the base by fire. A fungus gained
access through the wound and is
rapidly rotting the sapwood beneath.

may be prevented by taking proper care of the wounds. It should
not be assumed that the mere removal of the toadstool-like growths



on the trunk or branches of a tree will have any beneficial effect, for
these are the result of disease and not the real trouble. These
familiar fungus growths are found only on wood that has become
diseased as a result of some mechanical injury, which may have
occurred several years before. The treatment for such troubles, as
mentioned elsewhere, consists in removing the decayed wood con-
taining the fungus, sterilizing the wound, and protecting the tree
from further infection.

There are some leaf diseases, like the black-spot or "tar-spot" on
the Maple, that sometimes cause injury, but are seldom so serious
as to kill the tree. There are other tree troubles that affect the
leaves and which frequently cause serious alarm on the part of the
owner of the trees. A branch here and there and sometimes one-
half or more of the tree will show colored and dying leaves, many
of which fall about mid-summer. This trouble is especially com-
mon on the Sugar Maple, and it is sometimes very difficult to deter-
mine the cause. It is probably caused many times by an unbal-
anced condition of the tree. The Sugar Maple develops a large
growth of foliage in the spring, and during the dry months of July
and August the roots seem to have trouble in supplying enough
moisture to take care of the evaporation from the leaves. As a
result, some of the less favored branches lose their leaves. Trees

Fig. 72. Chestnut trees kiUed by the bark disease.



affected in this way usually leaf out again the following spring and
show no ill effects.

The most serious fungus pest of shade trees in the northeastern
states is the Chestnut-hark disease. Enormous tracts of chestnut
timber have been rendered worthless except for firewood. Orna-
mental chestnuts in parks and on private grounds also have been
killed in many sections. The total financial loss from the dis-
ease is estimated now at $25,000,000. The spores of the fungus
probably enter the bark through small wounds caused by birds,
insects, or abrasions. They commence growth in the cambium


Fig. 73. Diseased Chestnut bark showing pustules and form of discharge
of summer spores in damp weather. (Magnified 3 diameters.)



layer and the disease soon encircles the trunk of the tree, or a single
branch, as the case may be. All parts of the tree above the in-
fection dies, and if the infection starts on the main stem or trunk,
the whole tree is killed.

So far, no means has been devised for the prevention or control
of the disease. When valuable shade trees become affected in
one or more branches, the remainder of the tree possibly may be
saved by promptly cutting out the diseased portion. It is import-

Fig. 74. Diseased Chestnut bark
showing- pustules of the parasitic
fungus bearing winter spore

Lnt that the cut be made many feet below the point of infection to
avoid carrying the spores on the pruning saw. Great care also
should be exercised in avoiding injuries to the bark of the re-
maining portion of the tree. Tlie wounds made in cutting
out the diseased branches should be promptly painted with tar to
prevent further infection.


How Insects Injure Trees — The caterpillars, as well as some
beetles, injure the trees by devouring the leaves. A tree may be


completely defoliated without being killed. When the foliage is
destroyed early in the season a second crop of leaves usually ap-
pears. The necessity for furnishing a second supply of leaves
in one season weakens the tree, and if it is repeated for three or
four years, is likely to prove fatal. The condition becomes more
serious when the second crop of foliage is also destroyed. Without
foliage the tree cannot store up the necessary reserve material to
supply its needs the following spring.

Another class of insects, mostly grubs, cause injury by burrow-
ing under the bark and into the wood of trees. These are the
so-called borers. Occasionally one of these insects, like the Maple
borer, will completely girdle and cause the death of a tree in one
season, but usually they will work in a tree for many years before it
dies. The insects so weaken the trees that they are finally blown
over or broken down. To this class of insects belong some of
our more serious pests. Their destructiveness is because of their
habit of attacking a tree at its most vital point — the cambium —
and because their presence is not often detected until much dam-
age has been done. Even when they are known to be present they
are destroyed with great difficulty.

A third class of insects, including the bugs, scales, and plant lice,
injure the trees by piercing the tissue and sucking the juices. The
affected foliage becomes pale in color, curls up, and sometimes dies.
The bark also becomes infested and often large pits or indentations
are formed. With most members of this class, their great power
for destruction lies in their appearing in such enormous numbers
and in their power to reproduce so abundantly. Of the San Jose
scale, for example, there are three or four broods in a season, and
one pair of insects surviving the winter may by fall have progeny
numbering into the billions.

Methods of Comhatting Insects — In the control of insect pests
it is necessary to know something about their feeding habits. The
failure to get satisfactory results from spraying may usually be at-
tributed to the use of the wrong remedy. In the control of insects
that obtain their food by sucking, no benefit would be derived from
the application of stomach poisons, for it would be impossible to
get any of the poison into the insects' food. It is necessary,
therefore, to first determine to which class the pest belongs —
whether it is a chewing-insect or a sucking-insect.


It is well to determine also whether the insect causing the injury-
is in the larval or adult form. As a rule, injury is caused by in-
sects in the larval form only, but some species, like the Elm-leaf
beetle, feed during both the larval and adult stages. With insects
of the latter type it is always advisal)le when possible to destroy
them in the adult form before they have had a chance to deposit
their eggs, and in this way prevent the ravages of the second gen-

Spraying for Insects — The most common and the most satis-
factory method of controlling insects is by spraying. There are
many instances, however, where spraying is not practicable, and
there are many kinds of insects that cannot be controlled in this
way. The preparation and application of insecticides and the ap-
pliances used in the work will be discussed under the heading of
"Insecticides, Fungicides, and Spraying."

Hand-Piching of Insects — The large and conspicuous cater-
pillars often may be controlled by hand-picking. Their presence
usually may be indicated by their droppings on the ground. Cat-
erpillars that live in colonies or that build tents like the fall web-
worm and the tent-caterpillar, may be destroyed either by burning
with a torch or by cutting or brushing them out and dipping them in
kerosene. Conspicuous nests and Qgg masses like those of the gypsy,
tussock, and brown-tail moths, may be destroyed either on or off the
tree during the dormant season. Where small bounties have been
offered to school children, serious pests have been kept under con-
trol without further expense.

Borers also are usually controlled by hand-picking, ^ne saw-
dust-like castings around the base of the tree is an indication of
their presence. A sharp pocket knife, with which to dig the insects
out, will be found useful. A flexible wire or an old-fashioned
knitting needle sometimes may be used to kill the insect without
cutting into the bark.

Banding and Trapping — Man}^ ways have been devised for trap-
ping insects and thus preventing them from reaching their feed-
ing and breeding places. These methods of control are especially
useful on forest lands and other places where it is impracticable to
spray. Sticky bands and other obstacles tied around trees make it
possible to destroy many insects that congregate beneath the band
in their efforts to reach the foliage. This method is especially



useful with certain wingless moths that may be prevented from
depositing their eggs. The important point regarding their use
is to have them in position when the insects commence to crawl up
the tree.

The simplest band is made by using a strip of cotton batting,
about eight inches in width and Ions: enoudi to reach around the

Fig-. 75. Method of applying- sticky bands to protect trees from

tree and to lap over an inch or more. The batting is finnly tied
around the tree trunk at a point about six feet from the ground.


The twine used for the purpose should pass around the lower border
of the batting so that the upper border may be turned down, form-
ing an umbrella-like barrier.

The most satisfactory band is one made of sticky material like
"Tree Tanglefoot," a commercial preparation, which may be ob-
tained for about thirty cents per pound. After smoothing off the
bark it may be applied directly to the tree. Young, thin-barked
trees may be injured by direct contact and for this reason the
"Tanglefoot" may be applied to a strip of tarred roofing paper,
which may be attached to the tree. For ornamental trees it is usually
advisable to use the roofing paper, for this may be removed after
the trapping season is over. Where the bark is rough a narrow
strip of cotton batting may be placed beneath the paper to pre-
vent the insects from crawling beneath. (See fig. 75). Where
it is desirable to leave these bands on for more than one
season they should be recoated. Where the paper is tacked only at
the lap it will stretch sufficiently to accommodate at least one
year's growth. Bands put on in this way have been successfully
used for three or four seasons.

Night-flying moths are often trapped around electric lights.
Some insects, like the leopard moth, are hard to destroy in any
other way. The simplest way is to suspend beneath the light a
shallow vessel containing water with a layer of oil on the surface.
The moths are attracted to the light and accidentally drop in the

Online LibraryAlbert Francis BlakesleeTrees in winter; their study, planting, care and identification → online text (page 11 of 31)