CARE OF OLD TREES
The charm of many an estate is not the garden or the woodland, but the
monarchs that for years have weathered the winter storm and stand out as
noble specimens of their family. Often there are fine trees of rarer
species which their owners naturally wish to preserve from decay as long
as possible. Belonging to this class are numerous specimens scattered
over the country of American and other foreign trees that were amongst
the first of their kind to be introduced to Britain, such, for instance,
as the Tulip tree, the Robinia, and various oaks from America, the
Sophora from China, and various European trees. The trees may have some
historic associations, but whether this is so or not, when they begin to
decay efforts are made to save them from absolute death. Decay is
harmful and objectionable in park and garden, and we are not sure that
this matter of decay in trees has been so well considered as it might
be, as bearing upon the health of other trees and of mankind also. A
tree may be picturesque in decay, but we prefer it in health and beauty.
Experts are frequently asked for remedies to arrest decay in old trees.
The two principal causes of decay are starvation at the root and injury
by storms and disease. Such trees as the Beech and Horse Chestnut, that
root close to the surface of the soil--quite different from the Oak--may
often be invigorated by covering the ground with a few inches of good
soil or short manure. Artificial watering, during prolonged drought,
when thoroughly done, is also very helpful to the tree. Trees with large
crowns of branches are frequently seen thinly furnished with foliage,
and altogether sickly owing to unhealthy or insufficient roots. The
balance between top and bottom has been destroyed. To restore it in some
degree the top-growth may be reduced by pruning out and shortening back
branches here and there, wherever it can be done without spoiling the
appearance of the tree. This demands careful judgment, but some old and
sickly trees may certainly be restored in a measure by this help. It is
of no value in the case of trees with decayed trunks, nor with those
like our Common Oak, which will not break readily from old wood. But
Elms, Robinias, and Red Oaks are among those that respond to this
treatment.
Old trees with insecure branches can often be saved from destruction by
fastening the main branches together on to the trunk. The common
practice of putting an iron collar round the branch is a mistake. The
iron prevents the branch expanding naturally, and ultimately chokes it.
A better way is to use a strong iron rod with a plate at the end, and
instead of supporting the branch by encircling it, a hole is bored right
through the centre of it, through which the rod is pushed from the
outer side. The rod should be of tough iron or steel, and should exactly
fit the hole bored by the augur; the portions embedded in the wood
should be smeared with coal tar before they are pushed through, so as to
make the holes as nearly as possible air and water-tight. One end of the
rod should be "threaded" sufficiently to allow of the limbs being braced
slightly by screwing up the nut, and thus supporting some of their
weight. Finally, the bark should be neatly cut away so as to let in each
of the iron plates closer to the living wood, for by this means the time
required for closing over the plate by new wood is shortened. In this
way the weight is borne by the iron plate, which should, by removing
sufficient bark, be allowed to fit close in to the wood. New bark will
gradually close over and hide the plate, and instead of an ugly collar
cutting into the wood, the only evidence of artificial aid is the rod
coming from the inner side of the branch.
Branches or snags that have to be removed should be sawn off quite close
to the trunk or larger branch from which they spring. When a stump, even
not more than a few inches long, is left, the new bark and wood are
unable to close over it, and the wood ultimately decays and acts as a
medium for moisture and fungoid diseases. The saw should travel from
point A to B, as in the sketch. When a stump is left (as would be done
by sawing off at C D) decay sets in sooner or later. Although the tree
often succeeds in healing over the dead part, it more often fails to do
so until the decay has reached the trunk itself. With the softer-wooded
trees like the Horse-Chestnuts disease frequently reaches the heart of
the tree quickly by these means. A coating of liquid tar over the wound,
renewed once or twice until the new bark has closed over, is a sure
protection against these evils.
A good deal may be done in the early training of a tree to so control
its building up that it may best withstand the violence of gales. And
the most important matter in this connexion is the development of a
strong erect trunk, a central axis of such height and strength and bulk
as to be capable of supporting its head of branches easily. In other
words the leading shoot should always be watched, and, by the repression
of any rival leaders that may appear, allowed to retain its
predominance. In the best English nurseries only trees with good "leads"
are sent out.
[Illustration: When a broken stump, such as is here shown, has to be
sawn off, the proper place to amputate it is from A to B; the wrong
place from C to D.]
Trees decayed in the centre, with only an outer layer of healthy wood,
are, of course, doomed, but by filling up all holes in the earlier
stages of decay, and thus keeping out moisture, their term of life can
be lengthened by many years.
Holes made by woodpeckers can sometimes be plugged up with a piece of
Oak. This, if left on a level with the bark, will often enable the
latter to close over the hole. Large holes may be filled with cement, or
even built up with bricks, the surface being made water-tight and tarred
over.