Histories.ca - Download the EBook Scottish HistoryInformational Site Network Informational
Home - Origin of Arbor Day   Arbor Day Readings   Arbor Day Celebrations   Arbor Day Programs       Tree Species   Studies of Trees   New England Trees  

Study Iv Tree Repair

Where trees have been properly cared for from their early start, wounds

and cavities and their subsequent elaborate treatment have no place. But

where trees have been neglected or improperly cared for, wounds and

cavities are bound to occur and early treatment becomes a necessity.

There are two kinds of wounds on trees: (1) surface wounds, which do not

extend beyond the inner bark, and (2) deep wounds or cavities, which may

range from a small hole in a crotch to the hollow of an entire trunk.

Surface wounds: Surface wounds (Fig. 116) are due to bruised bark, and a

tree thus injured can no longer produce the proper amount of foliage

or remain healthy very long. The reason for this becomes very

apparent when one looks into the nature of the living or active

tissue of a tree and notes how this tissue becomes affected by such


This living or active tissue is known as the "cambium layer," and is

a thin tissue situated immediately under the bark. It must

completely envelop the stem, root and branches of the trees. The

outer bark is a protective covering to this living layer, while the

entire interior wood tissue chiefly serves as a skeleton or support

for the tree. The cambium layer is the real, active part of the

tree. It is the part which transmits the sap from the base of the

tree to its crown; it is the part which causes the tree to grow by

the formation of new cells, piled up in the form of rings around the

heart of the tree; and it is also the part which prevents the

entrance of insects and disease to the inner wood. From this it is

quite evident that any injury to the bark, and consequently to this

cambium layer alongside of it, will not only cut off a portion of

the sap supply and hinder the growth of the tree to an extent

proportional to the size of the wound, but will also expose the

inner wood to the action of decay. The wound may, at first, appear

insignificant, but, if neglected, it will soon commence to decay

and thus to carry disease and insects into the tree. The tree then

becomes hollow and dangerous and its life is doomed.

Injury to the cambium layer, resulting in surface wounds, may be due

to the improper cutting of a branch, to the bite of a horse, to the

cut of a knife or the careless wielding of an axe, to the boring of

an insect, or to the decay of a fungous disease. (See Fig. 117.)

Whatever the cause, _the remedy lies in cleaning out all decayed

wood, removing the loose bark and covering the exposed wood with

coal tar_.

In cutting off the loose bark, the edges should be made smooth

before the coal tar is applied. Loose bark, put back against a tree,

will never grow and will only tend to harbor insects and disease.

Bandages, too, are hurtful because, underneath the bandage, disease

will develop more rapidly than where the wound is exposed to the sun

and wind. The application of tin or manure to wounds is often

indulged in and is equally injurious to the tree. The secret of all

wound treatment is to keep the wound _smooth, clean_ to the live

tissue, _and well covered_ with coal tar.

The chisel or gouge is the best tool to employ in this work. A sharp

hawk-billed knife will be useful in cutting off the loose bark. Coal

tar is the best material for covering wounds because it has both an

antiseptic and a protective effect on the wood tissue. Paint, which

is very often used as a substitute for coal tar, is not as

effective, because the paint is apt to peel in time, thus allowing

moisture and disease to enter the crevice between the paint and the


Cavities: Deep wounds and cavities are generally the result of stubs

that have been permitted to rot and fall out. Surface wounds allowed

to decay will deepen in course of time and produce cavities.

Cavities in trees are especially susceptible to the attack of

disease because, in a cavity, there is bound to exist an

accumulation of moisture. With this, there is also considerable

darkness and protection from wind and cold, and these are all ideal

conditions for the development of disease.

The successful application of a remedy, in all cavity treatment,

hinges on this principal condition--_that all traces of disease

shall be entirely eliminated before treatment is commenced_.

Fungous diseases attacking a cavity produce a mass of fibers, known

as the "mycelium," that penetrate the body of the tree or limb on

which the cavity is located. In eliminating disease from a cavity,

it is, therefore, essential to go _beyond_ the mere decaying surface

and to cut out all fungous fibers that radiate into the interior of

the tree. Where these fibers have penetrated so deeply that it

becomes impossible to remove every one of them, the tree or limb

thus affected had better be cut down. (Fig. 118.) The presence of

the mycelium in wood tissue can readily be told by the discolored

and disintegrated appearance of the wood.

The filling in a cavity, moreover, should serve to prevent the

accumulation of water and, where a cavity is perpendicular and so

located that the water can be drained off without the filling, the

latter should be avoided and the cavity should merely be cleaned out

and tarred. (Fig. 116.) Where the disease can be entirely

eliminated, where the cavity is not too large, and where a filling

will serve the practical purpose of preventing the accumulation of

moisture, the work of filling should be resorted to.

Filling should be done in the following manner: First, the interior

should be thoroughly freed from diseased wood and insects. The

chisel, gouge, mall and knife are the tools, and it is better to

cut deep and remove every trace of decayed wood than it is to leave

a smaller hole in an unhealthy state. The inner surface of the

cavity should then be covered with a coat of white lead paint, which

acts as a disinfectant and helps to hold the filling. Corrosive

sublimate or Bordeaux mixture may be used as a substitute for the

white lead paint. A coat of coal tar over the paint is the next

step. The cavity is then solidly packed with bricks, stones and

mortar as in Fig. 119, and finished with a layer of cement at the

mouth of the orifice. This surface layer of cement should not be

brought out to the same plane with the outer bark of the tree, but

should rather recede a little beyond the growing tissue (cambium

layer) which is situated immediately below the bark, Fig. 120. In

this way the growing tissue will be enabled to roll over the cement

and to cover the whole cavity if it be a small one, or else to grow

out sufficiently to overlap the filling and hold it as a frame holds

a picture. The cement is used in mixture with sand in the proportion

of one-third of cement to two-thirds of sand. When dry, the outer

layer of cement should be covered with coal tar to prevent cracking.

Trees that tend to split: Certain species of trees, like the linden and

elm, often tend to split, generally in the crotch of several limbs

and sometimes in a fissure along the trunk of the tree. Midwinter is

the period when this usually occurs and timely action will save the

tree. The remedy lies in fastening together the various parts of the

tree by means of bolts or chains.

A very injurious method of accomplishing this end is frequently

resorted to, where each of the branches is bound by an iron band and

the bands are then joined by a bar. The branches eventually outgrow

the diameter of the bands, causing the latter to cut through the

bark of the limbs and to destroy them.

Another method of bracing limbs together consists in running a

single bolt through them and fastening each end of the bolt with a

washer and nut. This method is preferable to the first because it

allows for the growth of the limbs in thickness.

A still better method, however, consists in using a bar composed of

three parts as shown in Fig. 121. Each of the two branches has a

short bolt passed through it horizontally, and the two short bolts

are then connected by a third bar. This arrangement will shift all

the pressure caused by the swaying of the limbs to the middle

connecting-bar. In case of a windstorm, the middle bar will be the

one to bend, while the bolts which pass through the limbs will

remain intact. The outer ends of the short bolts should have their

washers and nuts slightly embedded in the wood of the tree, so that

the living tissue of the tree may eventually grow over them in such

a way as to hold the bars firmly in place and to exclude moisture

and disease. The washers and nuts on the inner side of the limbs

should also be embedded.

A chain is sometimes advantageously substituted for the middle

section of the bar and, in some cases, where more than two branches

have to be joined together, a ring might take the place of the

middle bar or chain.

Bolts on a tree detract considerably from its natural beauty and

should, therefore, be used only where they are absolutely necessary

for the safety of the tree. They should be placed as high up in the

tree as possible without weakening the limbs.

Tree Studies

How To Identify Trees
Group I The Pines
The White Pine (pinus Strobus)
The Pitch Pine (pinus Rigida)
The Scotch Pine (pinus Sylvestris)
Group Ii The Spruce And Hemlock
The Norway Spruce (picea Excelsa)
Hemlock (tsuga Canadensis)
Group Iii The Red Cedar And Arbor-vitae
Red Cedar (juniperus Virginiana)
Arbor-vitae; Northern White Cedar (thuja Occidentalis)
Group Iv The Larch And Cypress
The European Larch (larix Europaea)
Bald Cypress (taxodium Distichum)
Group V The Horsechestnut, Ash And Maple
The Horsechestnut
The White Ash (fraxinus Americana)
Sugar Maple (acer Saccharum)
Silver Maple (acer Saccharinum)
Red Maple (acer Rubrum)
Norway Maple (acer Platanoides)
Box Elder (acer Negundo)
Group Vi Trees Told By Their Form: Elm, Poplar, Gingko And Willow
American Elm (ulmus Americana)
Lombardy Or Italian Poplar (populus Nigra, Var Italica)
Gingko Or Maidenhair Tree (gingko Biloba)
Weeping Willow (salix Babylonica)
Group Vii Trees Told By Their Bark Or Trunk: Sycamore, Birch, Beech,
Blue Beech, Ironwood, And Hackberry
The Sycamore Or Plane Tree (platanus Occidentalis)
Gray Or White Birch (betula Populifolia)
American Beech (fagus Americana)
Blue Beech Or Hornbeam (carpinus Caroliniana)
Hackberry (celtis Occidentalis)
Group Viii The Oaks And Chestnut
White Oak (quercus Alba)
Black Oak (quercus Velutina)
Red Oak (quercus Rubra)
Pin Oak (quercus Palustris)
Chestnut (castanea Dentata)
Group Ix The Hickories, Walnut And Butternut
Shagbark Hickory (hicoria Ovata)
Mockernut Hickory (hicoria Alba)
Black Walnut (juglans Nigra)
Group X Tulip Tree, Sweet Gum, Linden, Magnolia, Locust, Catalpa,
Dogwood, Mulberry And Osage Orange
Tulip Tree (liriodendron Tulipifera)
Sweet Gum (liquidambar Styraciflua)
American Linden (tilia Americana)
The Magnolias