TREE-PRUNING
“Self-preservation is the first law of a tree’s life, and next to that the preservation of its species, which is to be perpetuated by means of seeds. All this is perfectly natural, for no posterity would be possible to the tree unless its own existence were maintained in the first place. Accordingly the tree lives first for itself, accomplishing this object by covering itself with buds that develop into branches covered with leaves. It is indeed on the leaves that the fundamental principles of the plant’s life are based; it is in their substance that, with the sun’s help, the descending sap is elaborated, this sap being the nutritive fluid, the life-blood as it were, of the vegetable organism. The propagation of the species comes next in importance. This duty devolves on the flower-buds or those that blossom and produce fruit, in the center of which are the seeds.
“Thus, left to its own impulses, a tree, if vigorous and enjoying favorable conditions, at first uses all its sap in making buds for the increase of its own woody structure; it covers itself with stout branches and abundant foliage before making up its mind to blossom. Later, when its limbs are strong and the [[117]]ardor of growth begins to abate, the flower-buds appear, but usually in small numbers because a prodigal production of fruit causes rapid decline. Copious blossoming comes only toward the latter part of life; a tree never blossoms better than when it is about to die, as if, foreseeing its end, it strove before succumbing to leave behind it a numerous progeny. A thriving tree blossoms little or not at all; a sickly tree makes haste to blossom. But it is to man’s interest that a tree should blossom and bear fruit as early and as abundantly as possible; we demand from it not the branches it would give us without our intervention, but baskets of fruit induced by our care. From this struggle between the natural tendencies of the tree and our own needs has sprung the practice of pruning, or the art of manipulating fruit-trees so as to obtain from them an abundant harvest.
“Here let us examine the general principles that are to guide us in the practice of this art. The shape to be given the tree’s superstructure of branches and foliage is the first question we must consider. This shape is far from being unimportant; it is, on the contrary, very important, since the circulation of the sap and the distribution of the sun’s rays, essential conditions to plant-life, are strictly dependent on it. If the tree is left free to develop by itself and to take its natural form, the sap from the roots will, under the impetus of its ascent, always seek by preference the highest points, where growth will in consequence proceed with vigor, [[118]]while the lower parts will languish and die out for want of sufficient nourishment. If the branches are not properly thinned the central ones, deprived of the sun’s vivifying rays, will remain poor, puny, more or less blanched. On the other hand, the tree ought to fill, as far as possible, the place assigned it, in order that there may be no unproductive space.
“These conditions prescribe the tree’s shape. First of all, it should be symmetrical, in order that the distribution of nourishment may be even and no part of the tree be gorged with sap while another part is deprived of it. Secondly, the sun’s rays should be allowed to penetrate everywhere so as to ripen the fruit and facilitate in the foliage the important work of sap-elaboration. To attain these different objects custom has fixed upon three principal shapes: the trellis, the pyramid, and the goblet. In trellis pruning the tree spreads its branches symmetrically, right and left, against a wall. The wall serves it as support and as shelter from the wind; it also gives the foliage and fruit additional heat and light by reflecting the sun’s rays upon them. When pruned to take the pyramid form, the tree has its branches so trimmed as to decrease in length regularly from the base to the summit and to remain far enough apart to admit the light to the center. The whole forms a sugar-loaf, a cone, into the midst of which sun and air enter freely. It is the shape most in accord with nature. Finally, the goblet-shaped tree has a certain number of branches of [[119]]equal vigor disposed in a circle around a central space that remains empty and thus receives its share of sunlight without hindrance.” [[120]]
CHAPTER XXV
PINCHING—BUD-NIPPING
“When the desired shape has been obtained the next thing is to keep it, despite all opposition on the part of the tree, which revolts in its own peculiar fashion; that is, it strives to restore the natural conformation of its branches. Suppose, for example, that a pear-tree, pruned after the manner of wall-fruit, has grown all out of symmetry and developed one side more than the other. How shall the two halves be restored to correct proportions? How shall the too vigorous part be weakened and the too feeble part strengthened? Several methods offer themselves.
“On the vigorous side let us cut back the branches with the pruning shears, leaving only the base of each with a small number of buds; in other words, let us cut them very short. On the weak side, on the contrary, let us leave the branches intact or cut them very long, thus leaving them the greater part of their buds. What will come of this treatment? Since abundant foliage, the active laboratory of the descending sap and also a kind of pump that sucks up the sap and causes it to ascend from the roots, is the prime cause of vigorous vegetation, the weak part, with its numerous buds developed into leafy [[121]]shoots, will grow stronger, while the strong part, with its small number of buds, will become weaker. Both effects will tend to the same result: the restoration of the desired symmetry.