The habit of early spring pruning has been handed down to us from
English customs, and farmers do it because it always has been done.
Besides, about this time, men have leisure, and would like to begin
the season’s work; and pruning seems quite a natural employment with
which to introduce the labors of the year.
It is not possible for America, but more emphatically for western
cultivators to do worse than to pattern upon the example of British
and Continental authorities in the matter of orchards and vineyards.
The summers of England are moist, cool, and deficient in light. Our
summers are exactly the reverse—dry, fervid, and brilliant. The
stimuli of the elements with them are much below, and with us much
above par. In consequence, their trees have but a moderate growth;
ours are inclined to excessive growth.
Their whole system of open-culture, and wall-training is founded upon
the necessity of _husbanding all their resources_. To avail themselves
of every particle of light, they keep open the heads of their trees,
so that the parsimonious sunshine shall penetrate every part of the
tree. Let this be done with us, and there are many of our trees that
would be killed by the force of the sun’s rays upon the naked branches
in a single season, or very much enfeebled. For the same general
reasons, the English reduce the quantity of bearing-wood, shortening a
part or wholly cutting it out, that the residue, having the whole
energy of the tree concentrated upon it, may perfect its fruit. Our
difficulty being an excess of vitality, this system of shortening and
cutting out, would cause the tree to send out suckers from the root
and trunk, and would fill the head of the tree with rank water-shoots
or _gourmands_. What would be thought of the people of the torrid zone
should they borrow their customs of clothing from the practice of
Greenland? It would be as rational as it is for orchardists, in a land
whose summers are long and of high temperature, to copy the customs of
a land whose summers are prodigal of fog and rain, but penurious of
heat and light.
Except to remove dead, diseased or interfering branches, do not cut at
all.
But if pruning is to be done, wait till after corn-planting. _The best
time to prune is the time when healing will the quickest follow
cutting._ This is not in early spring, but in early summer. The
elements from which new wood is produced are not drawn from the rising
sap, but from that which descends between the bark and wood. This sap,
called _true sap_, is the upward sap after it has gone through that
chemical laboratory, the leaf. Each leaf is a chemical contractor,
doing up its part of the work of preparing sap for use, as fast as it
is sent up to it from the root through the interior sap-passages. In
the leaf, the sap gives off and receives, certain properties; and when
thus elaborated, it is charged with all those elements required for
the formation and sustentation of every part of vegetable fabric.
Descending, it gives out its various qualities, till it reaches the
root; and whatever is left then passes out into the soil.
Every man will perceive that if a tree is pruned in spring before it
has a leaf out, there is no sap provided to repair the wound. A slight
granulation _may_ take place, in certain circumstances, and in some
kinds of plants, from the elements with which the tree was stored
during the former season; but, in point of fact, a cut usually remains
without change until, the progress of spring puts the whole vegetable
economy into action.
In young and vigorous trees, this process may not seem to occasion any
injury. But trees growing feeble by age will soon manifest the result
of this injudicious practice, by blackened stumps, by cankered sores,
and by decay.
If one must begin to do something that looks like spring-work, let him
go at a more efficient train of operations. With a good spade invert
the sod for several feet from the body of the tree. With a good
scraper remove all dead bark. Dilute (old) soft soap with urine; take
a stiff shoe-brush, and go to scouring the trunk and main branches.
This will be labor to some purpose; and before you have gone through a
large orchard faithfully, your zeal for spring-work will have become
so far tempered with knowledge, that you will be willing to _let
pruning alone till after corn-planting_.
Two exceptions or precautions should be mentioned.
1. In the use of the wash; new soap is more _caustic_ than old; and
the sediments of a soap barrel much more so than the mass of soap.
Sometimes trees have been injured by applying a caustic alkali in too
great strength. There is little danger of this when a tree is rough
and covered with dead bark or dirt; but when it is smooth and has no
scurf it is more liable to suffer. _Trees should not be washed in dry
and warm weather._ The best time is just before spring rains, or
before any rain.
2. Where fruit-trees are found to have suffered from the winter,
pruning cannot be too early, and hardly too severe. If left to grow,
the heat of spring days ferments the sap and spreads blight throughout
the tree; whereas, by severe cutting, there is a chance, at least, of
removing much of the injured wood. We have gone over the pear-trees in
our own garden, and wherever the least affection has been discovered,
we have cut out every particle of the last summer’s wood; and cut back
until we reached sound and healthy wood, pith and bark.