This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
Fruit trees of all kinds flourish so luxuriantly in the open air in America, that it would, at first sight, seem perfectly unnecessary to provide them with glazed roofs, and nurse them up in pots; but when we recollect that the curcnlio destroys most of our plums and nectarines, that both them and the peach are prone to a luxuriance incompatible with the "highest degree of fruitfulness, that mildew in various forms continually insinuates itself and makes sad havoc with our calculations; not to more than mention grubs and borers, late spring and early autumn frosts, the cutting, blighting winds of spring and wilting droughts of summer, quite a formidable array of calamities can be enumerated, without infringing upon truth, as every grower of these fruits has but too good reason to know.
In the orchard house, all these conflicting opponents to success may be avoided; the curculio is too cunning to be caught under roof, and the borers will seldom be found under glass if the trees are free of them when introduced; the atmosphere is so completely under control that mildew and all other maladies consequent upon sudden and extreme changes may be prevented.
Many of these advantages, however, are only incidental. Earliness of bearing and continued productiveness are the essential characteristics; the certainty of the crop, as well as the ready means of accelerating the ripening, are also subjects worthy of note.
In all fruit-bearing trees a certain maturity has to be attained before fruit is produced; and the period when this takes place depends much on local circumstances. "Whatever produces excessive vigor in plants is favorable to the production of leaf buds, and unfavorable to the formation of flower buds; while, on the other band, such circumstances as tend to diminish luxuriance, and to check rapid vegetation, without affecting the health of the individual, are more favorable to the production of flower buds than of leaf buds." When a tree is planted in a deep, rich soil, in a climate congenial to its growth, the fruiting period will be the longest deferred; from the encouragement to the extension of roots, branches will be produced with a barren luxuriance for many years. Whereas, a tree set in poor ground will make feeble growths, but will blossom and fruit at an early period, although such fruiting may be the means of seriously weakening it; some trees will thus fruit themselves to death. This is a well-known law, and has been acted upon by various expedients, such as root pruning, bending down branches, ringing, etc.
The most popular, because most available, method of inducing fruitfulness at present, is that of modifying excessive vigor by grafting, or otherwise introducing those of robust growth on stocks of weaker habit, familiarly known as the "dwarfing system." This practice is followed with more or less success, according as experience discovers the peculiarities of growth and constitutional vigor of individual trees.
It is very obvious that the limited amount of soil in a pot will speedily be interwoven with roots; growth will then be checked and fruit buds formed; it is equally apparent that these conditions must limit the quantity of fruit that can be matured. Here the orchard house system becomes valuable; the pots being set on a border of soil early in their growth, young roots find access into it through openings left for that purpose, and thus the plant is provided with an extra supply of nourishment during the period of formation and ripening of the crop; the roots thus produced being removed when the crop is perfected, all tendency to redundant wood-growth is checked, and the branches are again thickly studded with fruit buds.
The greatest objection to this course of culture is its expense, involving, as it does, much care and time, in watering and other necessary attentions, neglect of which will inevitably be followed by failures. These objections might be partly obviated by setting out the plants in permanent borders; and to guard against over luxuriance in the first stages of growth, and deficiency of nourishment in the future, let spaces be left between the plants for root pruning and additions of fresh soil, as either of these operations is demanded. The following figure shows the section of an orchard house arranged according to the above suggestion.
SECTION OF AN ORCHARD HOUSE.
The trees are planted in the spaces a a a. The spaces b b to be filled with soil during summer, removed altogether after the crop is gathered, or turned over so as to disturb the roots sufficient to check growth. The walls each side of these spaces to be built pigeon-hole fashion, so that a communication may be provided for the roots. The shelves c c will be useful for strawberries in pots, or other similar purposes. The heating apparatus, if any is required, is placed at d.
This arrangement secures all the advantages of a system of pot culture, and would be equally productive and easier of management. The larger body of soil would retain moisture for a longer period, and daily visitations of the watering pot would not be required.