CHAPTER X.

PHILOSOPHY OF PRUNING.

PRUNING, NATURE'S. WE PRUNE, FIRST, FOR SHAPE AND COMELINESS; SECOND, FOR FRUIT. PRUNING YOUNG TREES IN THE NURSERY. RULES FOR. SEASON FOR. PRUNING FOR FRUIT IS TO BE DONE CHIEFLY IN SUMMER. THINNING OUT. SHORTENING-IN. ROOT PRUNING. PHILOSOPHY OF. ADVANTAGES OF. CHARACTER OF ROOTS PRODUCED BY IT. IN THE VINE. SEVERE IN WINTER TO PRODUCE WOOD AND DIMINISH BLOSSOMS. ADAPT TO VARIETIES. IN SUMMER TO DIMINISH EXCESSIVE FRUITAGE, AND TO DIRECT SAP INTO NEW CANES. TRIMMING IN GARDENESQUE, REQUIRING A CORRECT EYE AND GOOD TASTE. PRUNING SHOULD BE CONDUCTED UPON TRULY PHILOSOPHICAL PRINCIPLES, OR NOT AT ALL. QUALIFICATIONS REQUIRED IN THOSE WHO PRUNE. THE OPERATION SELDOM WELL PERFORMED. PRUNING OF THE GRAPE, SHORT AND LONG. REASONS FOR AND OBJECTIONS TO EACH. SEASONS FOR PRUNING THE VINE.

Pruning is one of the most important operations that we perform upon plants,--especially woody plants. Pruning, in some sort, has to be performed at all periods of their existence and growth, and upon all plants, from the noble forest tree, or the fruit trees of the orchard, of whatever kind, to the humble bushes and brambles that yield us their abundant and most welcome fruits: the trailing vine that adorns our arbors and covers our trellises with its rich and tempting clusters of grapes, also needs to be pruned. Many herbaceous plants are also submitted to judicious pruning, and yield in consequence an increased product of fruit. Our ornamental gardeners and plant-growers practice pruning most admirably upon their house-plants, and by their successful practice, they produce the most wonderful effects, which are manifested in the vigor, thrift, symmetry, and blossoming of their specimens.

And yet, when we come to travel about the country, and to see the shrubberies, the parks, the orchards, fruit-gardens, and vineyards, as they are, we shall be struck with the great amount of ignorance or neglect manifested by what we everywhere behold! Still more shall we be surprised, when we hear nurserymen and orchardists, men who have had opportunities for extended observation, and those too, who are considered successful cultivators, advocate the idea that trees should not be pruned at all. An apology may be found for them in the many instances of bad pruning that may frequently be met with. They may say that no pruning is better than such mutilation, and with some varieties of fruit, they may have a show of reason on their side, as there are many sorts that will very naturally produce an open head, every where provided with abundant fruit-spurs, which are the great desiderata of the fruit-grower.

We prune our plants for the most opposite purposes; we prune to make them assume some desired form, we prune to produce symmetry, and we prune to torture them as much as possible from their natural habit. Again, we prune to make them grow vigorously, and we perform other pruning operations, in order to dwarf and stunt our specimens, and to make them as diminutive as possible. The experienced orchardist will tell you to prune a barren but thrifty tree, in order to make it productive of fruit; and he will also tell you to _prune_ one that has expended all its energies in fruit-bearing, and appears likely to exhaust itself to its own destruction. Upon very high authority, supported by universal and annual practice, the vine dresser will tell you to prune your vine in order to make it fruitful; the same authority will advise you to prune in such a manner as to prevent an over-production--and he will insist that you shall prune again during the season of growth, to promote the same objects.

Thus it appears that the ends to be attained by this important operation are exceedingly diverse, and apparently contradictory: nor is it any wonder that the novice should feel bewildered in the midst of directions so opposite, nor even that those who have grown gray in the orchard, should have arrived at the strange conclusions just mentioned, _not to prune at all_. And yet, notwithstanding these apparent contradictions, there is a reason for each of these various modes, as well as for the different seasons that have been recommended for performing the several operations of pruning.

It may be said that in natural trees, whether standing alone in the midst of a prairie, thinly grouped in the "opening," or crowded together in the dense forest, we may behold the most perfect models of beauty and fruitfulness; yet these have never been subjected to the action of the knife, the saw, nor the hatchet. True, and yet they have all been pruned by _nature_. She prunes and trains magnificently, and gives us the finest models for imitation, whether for park scenery, as in the lone tree of the prairie, or in the scattered groups of the island groves that are so often seen in the broad savannas of the West, or in forests of noble shafts, gazed at with admiration, then felled by the ruthless ax, and converted to man's economic uses. She also shows us the pattern in the dense pineries, and other timber tracts of our country. All these have been pruned into their present condition by the hand of nature. In the single specimen, free access of air and light have enabled it to assume its full proportions, developing itself on every side, and giving us the grand and beautiful object we behold. The winds have tossed the branches and some have been broken, the lower ones have quietly and gradually yielded to the smothering influence of those above them, which, in turn, have swept downward toward the ground. In the groves, the scattering trees have for a while enjoyed the same opportunities for development; but at length their branches have met together, and interlocked in friendly embrace. Those that were nearest the ground had already begun to suffer from the denser canopy above them but the great sturdy boughs that had shot upward so as to form a part of the crown, were able to retain their vantage ground, and continue as important members of the trees. In these illustrations, we have seen more of nature's training than of her pruning; but it must be remembered that training is one of the objects, and indeed, a leading element of pruning, and is very properly a matter for our consideration.

In the dense primeval forest we see nature's pruning exhibited upon a grand and perfect scale; tall, straight, and noble trunks rise majestically on every hand; not a twig nor limb breaks the symmetry of the gradually tapering shafts, that are clothed in bark which does not indicate that they had ever been furnished with branches; and yet they have borne branches from their base to their summit, and nature has so neatly removed them that we cannot detect the marks of her pruning-saw. How this has been effected, may be seen in any dense thicket of young forest growth. It is simply a smothering of the lower branches by those next above them, which has destroyed their vitality, and their decay has soon followed; while a new growth of branches at a higher point, in turn, performs the same office of destruction upon those next below them. As there is no outlet for the wood-growth but in an upward direction, upwards they must needs go, and as there is no light nor air for lateral branches under such a canopy of shade, death and decay ensue, and down they perforce must come.

If it be asked why we prune at all, it may be answered in general terms that in the orchard, our objects in performing this operation, are two-fold.

1st--We prune for shape and comeliness, and for the removal of dead and dying branches, in aid of nature, but working in sympathy with her.

2d--We prune for the sake of inducing fruitfulness.

Let us consider some of the principles that are to guide us in these operations.

The first object, that of producing the desired shape of the future tree, is chiefly done upon the young subject, even in the nursery-row. The judicious pruner, being well aware of the upward tendency of young growth, and that this is increased by the crowded condition of the trees in the nursery square, seeks to overcome the evil by proper pruning. If the growth be altogether upward, with no side branches the first season, the stem will be slender, often so much so as to bend over with its own weight. The wise nurseryman carefully avoids disturbing the leaves or lateral branches, well knowing their importance in forming the woody trunk. At the proper season he trims his trees down, instead of trimming them up--this he does by heading them back to the hight at which he desires them to form their branches--at the same time, he shortens in the laterals; his object in both instances being to check the upward tendency of growth by removing the strong terminal buds, which would naturally have formed the new shoots the coming season. The result of this treatment is to call into action several buds at the upper part of the stock. These are to form the arms of the tree, and hence a very important part of the pruning and training of the plant is thus performed at once by this simple operation of heading-back the young nursery tree. But further attention is needed, as these arms develop themselves during the next season of growth; they should not be too numerous, nor too much crowded together; they should not be too nearly matched in strength, and one should be kept as a leader, stronger than the rest. Never allow two shoots to remain contending for the mastery; one of them should be subordinated by cutting, breaking, or twisting, as soon as it is observed; for how beautifully developed, a tree grown in this way, may appear when well balanced, there is always danger of its splitting down when heavily laden with fruit. This very common error of our orchards used to be quaintly illustrated by a dear old friend on the prairies of Illinois, who cited the advice of a Scotch jockey to whom he had applied for counsel in the purchase of a piece of horse-flesh. "Ne'er buy a horse whose twa fore-legs cum oot frae ae hole," said he, and Mr. W. Stewart applied the same principle to his young fruit trees, by never allowing them to have two equal leaders, branching from one point. It is also important to have the lateral branches regularly distributed on different sides.

The precise point or elevation point at which this heading-back should be done, will depend very much upon the object of the cultivator, and whether he desires to produce a high or a low head, a standard, half standard, or a dwarf, or conical tree--such as are often called pyramids. He will study the wants and fancies of his customers in this matter, but we of the West, have learned the importance for us, at least, of _trimming our trees down_, and not trimming them up, as is often done by those who anticipate plowing and planting crops under the shade of their orchards. The proper point for forming the branches to make the head, will very much depend, however, upon the habit of the variety; whether it be drooping, spreading, or upright. The former will require the branches to be started at a higher point. The proper season for performing this kind of pruning is in the early spring, or after the severe frosts of winter have passed; and with some kinds of orchard trees, it may be done at the time of transplanting them, when they need a severe pruning.

The second object of pruning being done with a view to the production of fruitfulness in the tree, is to be practised chiefly in the summer. At the same time, or during the growing season, much may be done to advantage, both in thinning-out and shortening-in such parts of the tree, as may need these plans of treatment. Various methods are pursued to produce fruitfulness, all of them depending upon the fact that this condition arises from the natural habit of a tree to make its wood-growth freely for a series of years. After it has built up a complicated structure of limbs and branches, with some consequent obstruction to the flow of sap, depending upon the hardening of the woody tissues, and the tortuous course of its circulation, it then appears to have reached its maturity, or its fruit-bearing condition. It then ceases to make such free wood-growth, and prepares a set of buds, which develop flowers and fruit.

Now this period of growth and unfruitfulness may continue for a longer or shorter time in different varieties of fruits; and the shortening of this, is the great object of summer pruning, and of other methods of producing fruitfulness that may be classed under this second head of the objects of pruning.

To appreciate their importance and the mode in which the effect is produced, we must ever bear in mind the two great acts of vegetable life, that of wood-growth or growth by extension, and the wonderful morphological change of this growth into flowers and fruit. These are, in some sense, antagonistic. The first is essential to the production of timber, to the building up of the tree, and should be encouraged to do its work undisturbed, up to a certain point, that we may have a substantial frame-work by which our fruits can be supported. The latter, however, is the ultimate desideratum with fruit-growers, and in our impatience to reap a quick reward, we often resort to measures that tend to curtail the usefulness, size, and beauty, as well as the permanence of our trees. This is an illustration of the axiom, that whatever threatens the vitality of a plant, tends to make it fruitful; it calls into activity the instinctive effort to perpetuate the species by the production of seed, that may be separated from the parent, and establish a separate and independent existence, to take the place of that, the life of which is threatened.

Summer pruning and pinching interferes with the growth by extension, and threatens the very life of the tree; the entire removal of all new shoots and their foliage, and the removal of the successive attempts by the tree at their reproduction, will cause its death in a little while. Their partial abstraction, as practiced in summer pruning and pinching, being an attack of the same kind, results in the formation of fruit-buds. The operations of budding and grafting upon an uncongenial stock, interrupting the circulation by ringing, by ligatures, by hacking, twisting, and bending downward, all tend to check the growth by extension, and are attended by similar results, since they are antagonistic to the mere production of wood. Shortening-in the branches of some species, which form their fruit-buds upon the shoots of the current year, has the effect to give them a fuller development, if performed during the summer, but if deferred until the following spring, it will have the directly opposite result, and will cause the production of woody shoots at the expense of the fruit.

The season for pruning has been made the subject of much discussion, and different periods have been very confidently advised by different authorities, from which it may safely be inferred that all are somewhat right, or may be supported by good reasons. This refers of course to pruning in its general sense, of trimming, and applies to the removal of limbs of greater or less size. We always desire to avoid the removal of large limbs, and should endeavor to provide against the necessity of such removal, by trimming our orchards sufficiently when they are young, and while the branches are small; but when such removal becomes absolutely necessary, it should be performed late in the autumn, when vegetation is at rest, because it is found that such large wounds, which cannot be soon healed over by the new growth, will at this season dry in, and resist the action of the elements better than if the section had been made when the wood was full of sap in active circulation.

Early spring is a favorite period for pruning, chiefly because it is comparatively a period of leisure; the weather is less inclement than in winter, and the absence of foliage affords us an opportunity to see our work and to anticipate its effects upon the tree. So soon as the buds begin to swell and the foliage to expand, pruning should be arrested, unless in small trees, because the sap is in active motion, and the material called _cambium_ is not yet developed, hence the wounds will bleed, and are not so readily healed over; besides, the bark at this season is very readily separated from the wood, and bad wounds are thus frequently produced by the pruner, which may seriously damage the tree. Then follows a period when pruning had better be suspended until the time that the trees have completed their growth by extension, and formed the terminal bud at the ends of their shoots. The date cannot be given, but it is sufficiently indicated by this mark in nature's calendar; the formation and full development of the terminal bud, and by the copious deposits of woody matter throughout the tree. The annual layer of fibres is then being produced, and the tissues are in the formative stage; the tree now possesses within its own organism the best of all plasters to cure and cover the wounds made by the saw and knife, now the tree possesses the true _vis medicatrix naturæ_ in the highest degree.

A few intelligent nurserymen have learned this very important lesson, and have applied it in the preparation of their trees, for the exposure incident to their removal from the nursery to the orchard. A very few practice it systematically; I knew one, (alas, for the lamented Beeler, of Indiana), who acted upon the suggestion made to him by observations and experiments in vegetable physiology. He left the side branches, though subordinated by shortening when necessary, in order to give stocky stems to his trees, and then removed them with the knife during the summer before they were to be sold and planted, instead of waiting until they were dug and sent to the packing house in the fall or spring. The result was, that while his stems were stout and stocky, they were also smooth, the wounds neatly healed over with new bark, instead of being open from the fresh cuts and liable to crack or bleed, as they would have done had this pruning been deferred until after digging, either in the fall or spring. This may be considered a small matter, but it is an illustration of the principle involved in selecting the period for pruning.

For the removal of small limbs from young trees, hardly any time can come amiss--better to do it out of season than to neglect it, and it is a good rule to have a sharp pruning knife always at hand when passing through our young orchards. There is but one time when pruning is absolutely interdicted, and that is when the wood is frozen. When so circumstanced, it should never be cut nor disturbed in any manner--not even to gratify your best friend, by helping him to a few grafts from your proved tree of some coveted variety. Let him wait for a thaw, or go away without the grafts, rather than commit such an outrage upon your tree: as to approach it with a knife when frozen.

While considering the question of the proper season for pruning, there is one axiom of great importance which should be firmly impressed upon the mind of the orchardist. Much will depend upon which of the two leading objects, above indicated, he may have in view--vigor of growth and symmetry of form, or simply fruitfulness, as the result of his labors in pruning his trees. Pruning at one season will induce the former result, at a different period of the year the same work will conduce to the latter; hence the postulate _Prune in winter for wood; in summer for fruit_.