Dwarf Fruit Trees Part 3

The formation of trees into bushes and pyramids, by means of systematic pruning according to a definite plan, as explained in the succeeding chapters, while apparently simpler and more reasonable to our American eyes, it is still a method of training the tree. The fruiting branches are placed at definite points and the fruit spurs are encouraged to grow in regular succession. It is not a very great step from this to a distribution of the branches into a more precise form.

The different forms which are used most commonly are named and cla.s.sified in the following outline:

_A._--_Forms of three dimensions_: _a._ Vase or bush _b._ Pyramid _c._ Winged pyramid, etc.

_B._--_Forms of two dimensions_: _a._ Various espaliers _b._ Palmette-Verrier _c._ Fans or Fan-espaliers _d._ U-form and double U-form _C._--_Trained to a single stem_: _a._ Upright cordon _b._ Oblique cordon _c._ Horizontal cordon (with one arm) (with two arms) _d._ Serpentine cordon, etc.

Among the forms of three dimensions none is of much practical importance besides the pyramid and bush or vase form. These are sufficiently explained in the chapters on pears and apples. Here we need only to define them. The pyramid tree is one which has a straight central stem with branches radiating therefrom. It is especially adapted to upright growing varieties of pears. The bush or vase form has several main arms or branches, all standing out from approximately the same point and growing upward at a more or less acute angle, thus forming roughly a vase. The secondary branches put out from these, bearing fruiting wood, as the gardener may order.

[Ill.u.s.tration: FIG. 15--PEARS IN DOUBLE U-FORM

From Loebner's "Zwergobstbaume"]

The flying pyramid or winged pyramid, described in all European books, is considerably different from the ordinary pyramid and is more precise in its design. Usually six arms are brought out at the base of the tree.

These are grown in a direction approximately horizontal until they reach a convenient length,--say two to three feet. They are then suddenly bent upward and inward and are conducted along wires set for this purpose until they meet in a common point with the main stem of the tree some four to eight feet above where the branches put out. There is thus formed a precise mathematical pyramid. Along these main arms fruiting spurs are allowed to grow, but no branches are expected to develop.

Sometimes the flying pyramid is made more elaborate by bending the arms into a spiral form. Other more or less complex modifications are practised to some extent. All of them are to be regarded merely as curiosities and as of no practical value.

The various forms of espaliers and fan-shaped trees have their special and legitimate uses. It may be said here that the Palmette-Verrier is regarded generally as being the most successful for the largest number of varieties of fruits. It is a safe rule also that the simpler forms are generally the better. With rare exceptions a tree confined to a moderately small s.p.a.ce is more satisfactory than one trained over a large s.p.a.ce.

Great care must be exercised in forming these trees. If the geometrical style of training is undertaken at all, it should be carried out with considerable precision. If one arm happens to be placed a little higher, or at a little more moderate angle, or otherwise more favorably than the corresponding arm, it will very soon divert to its own use the major portion of food supplied by the top. It will outgrow its mate and the form which the gardener designed will eventually be lost. It will be seen at once that this condition makes the same care and precision necessary in all forms of training.

[Ill.u.s.tration: Fig. 16--PEARS IN U-FORM

Sometimes called two-arm upright cordons]

The U-form cla.s.sifies somewhere between the cordon and the espalier. It consists of two upright branches joined to a single trunk below by an arc of a circle. The fruit is all borne on the two parallel stems which are treated essentially the same as upright cordons. (Fig. 17.)

The double U-form is made by growing two U's from the same tree. The stem is first divided near the ground into two branches and each of these is immediately divided into two more. The tree thus provides four parallel and equally s.p.a.ced upright and fruiting stems equal to four upright cordons, except that they are all supported from a single trunk.

The U- and double U-forms are employed mostly for plums, apricots, peaches and nectarines.

One occasionally sees much more elaborate schemes of training than any here mentioned. There are complex geometrical designs, even pictorial figures--birds, dogs, and beer-steins--and sometimes the initials of the gardener, or the name of his kingly and imperial majesty. In every case the method of producing these forms is practically the same. A frame is built of wood or wire in the form which it is desired to give the tree.

Branches are developed at suitable points on the tree and these are tied out while they are growing to the wooden or metal form. It does not require any special care or ingenuity to produce the most elaborate designs in this method. It is essentially a job of carpentry.

[Ill.u.s.tration: FIG. 17--APRICOTS IN U-FORM]

We come now to the cordons. If we take the simplest form, namely the upright cordon, we have what we may call a tree of one dimension only.

The upright cordon has nothing but height, eschewing both breadth and thickness. A cordon is simply a tree trained to a single stem and this stem may be placed in any position. The position or direction of the stem cla.s.sifies the cordon. There are, therefore, besides the upright cordon, others which are oblique, that is, which make an angle with the horizontal, those which are horizontal, and those which are bent into various forms. The serpent form is one of the simplest of these. This form of cordon is simply bent back and forth against a trellis forming a series of S's one above another. The horizontal cordons are of two varieties, namely one-arm and two-arm forms. It is altogether a matter of convenience which one of these forms is chosen.

[Ill.u.s.tration: FIG. 18--PEAR IN ESPALIER

This tree is carrying over 200 fruits]

In conclusion it may be pointed out that the slower growing trees, pears and apples, are the better suited to the more elaborate forms of training. The more free and rapid growing species, such as peaches, nectarines, cherries, and j.a.panese plums, are better managed in somewhat simpler forms, preferably the fan. Such trees do well, however, in the U-form or double U-form.

[Ill.u.s.tration: FIG. 19--OLD ESPALIER PEARS ON FARM HOUSE WALL]

VI

GENERAL MANAGEMENT

The general management of dwarf trees is naturally very much like the management of ordinary standard trees. As dwarf trees are grown more often in gardens rather than in orchards they will receive garden treatment. Heavy tools and extensive methods of culture will hardly find application.

Good soil culture may be regarded as essential. Whatever some American fruit growers may be saying about the propriety of growing apple orchards in sod, no one has yet undertaken to adapt the sod system into the kitchen garden. The close planting which is customary with dwarf trees makes culture comparatively difficult, yet not unreasonably so.

Apple and pear trees planted six feet apart each way can be worked for several years with a single horse and cultivator. In fact if the trees are kept carefully headed in, the time need never come when the cultivator will have to be abandoned. When cordons or espaliers are planted in a garden large enough to warrant horse cultivation under ordinary circ.u.mstances then the rows of trained trees should be set six feet apart, which will be enough to permit the continued use of the horse and cultivator between the rows.

[Ill.u.s.tration: FIG. 20--HORIZONTAL CORDON APPLE AND OTHER DWARF TREES

With cover crop of hairy vetch]

However, the horse cultivator is certain to be definitely crowded out of some dwarf fruit gardens. Many of the men who have greatest reason for growing dwarf fruit trees are those whose backyard gardens were never large enough to justify the presence of a horse or horse tools. In such cases the spading fork and the hand cultivator are the ready and proper subst.i.tutes. Our extensive methods of farming in America have bred a strong prejudice against all sorts of hand labor like this, but experience will show that under some conditions it is quite worth while.

A very common mistake in all kinds of agriculture is to allow prejudice to rule experience.

[Ill.u.s.tration: FIG. 21--DESIGN FOR A BACK YARD FRUIT GARDEN 50 FT.

SQUARE

North fence (top of map), peach espalier (4); Row 1, bush apple (7); Row 2, pyramid pear (7); Row 3, currants and gooseberries (11); Row 4 and 5, horizontal cordon apples, with gra.s.s walk between; Row 6, raspberry bushes (7); Row 7, strawberries; Row 8, plums in bush form (7); Row 9, apples in horizontal cordons (4); East fence, apples as upright cordons (31); West fence, pears in espalier.]

Garden culture means not only good tillage of the soil, but good treatment in other respects. It means good feeding and good spraying. As for spraying we need make only two observations. First, the treatment to be given is almost precisely the same as that which is given to standard trees of the same species; second, the work is much more easily performed because the trees are smaller. If one happens to have a considerable block of dwarf trees closely planted. There may be difficulty, it is true, in driving in with a spray pump. This difficulty is overcome by having long runs of hose on the spray pump, so that the cart may stand on the borders of the garden while the operator carries the nozzle in among the trees. In case of large plantings of dwarf trees alley-ways should be left every one hundred feet, or better, every eighty feet, between the blocks. These alleys will be useful for other purposes besides spraying.

[Ill.u.s.tration: FIG. 22--DWARF FRUIT GARDEN 111 BY 144 FEET

From Lucas' Handbuch des Obstbaues]

In the management of a small garden the gardener is expected to be liberal in his allowance of fertilizers. While it is true that dwarf fruit trees should be liberally fed there is a possibility of overdoing it. It has already been explained that the dwarfing of the tree depends in a certain way on its well-regulated starvation. If the tree top could get all the food which its nature calls for it would not be dwarfed. The rule in feeding dwarf fruit trees therefore should be to give enough fertilizer to keep them in perfect health and in good growing condition, but not enough to force unnecessary growth. Fertilizer rich in nitrogen should be especially avoided, and, as the object in view is to secure an early maturity of the tree and to produce fruit always in preference to wood, a larger proportion of potash would naturally be subst.i.tuted for the diminished proportion of nitrogen. Of course the amounts and proportions of the different elements (nitrogen, potash and phosphoric acid) to be applied will vary greatly with different conditions,--with the nature of the soil, the age of the trees, etc. As a sort of standard we may say that under normal conditions of good soil with dwarf apple and pear trees in bearing there should be given annually for each acre:

400 pounds ground bone 400 pounds muriate of potash 100 pounds Peruvian guano

Peaches and plums require more nitrogen during early growth, and more potash when in full bearing. For a new plantation of these trees the following amounts should be given annually for each acre:

300 pounds ground bone 400 pounds muriate of potash 150 pounds nitrate of soda

For peach and plum trees in bearing, the following formula may be suggested:

400 pounds ground bone 500 pounds muriate of potash 100 pounds Peruvian guano

Inasmuch as many owners of dwarf fruit trees will have so much less than an acre for treatment it will be best to repeat these formulas, reducing them to a smaller unit. Making this reduction somewhat freely, in order to avoid long and useless decimals, we may compute the quant.i.ty needed annually for each one hundred square feet of land as follows:

FOR APPLES AND PEARS IN BEARING

1 pound ground bone 1 pound muriate of potash 1/4 pound Peruvian guano

FOR PEACHES AND PLUMS NEWLY PLANTED

3/4 pound ground bone 1 pound muriate of potash 3/8 pound nitrate of soda