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.
Although the cultivation of fruits in pots under glass has been to a limited extent practiced for very many years in the forcing houses of large establishments, (and for which the mode of potting that has been above described is applicable,) the system of growth now usually referred to, under the designation of "Orchard Houses," is. comparatively of recent date; it having been brought before the horticultural world in England about a dozen years ago by Mr. Thos. Rivers, a well-known nurseryman at Sawbridgeworth. The principal feature of the excellent system advocated by him consists in the growth of trees through the year by the joint agency of the earth in the pots containing the trees, and that of a border of rich earth upon which the pots are placed, and into which their roots penetrate through holes left for the purpose in the bottom of the pot. And as these roots (in the border) are periodically cut off in the course of the annual culture, it will be apparent that the condition of the plant is not so dependent upon the earth in the pot: because, in addition to the nourishment supplied by that, a great degree- of stimulus can be given to the plant by increasing the richness of the, border; and the excitement to growth, if too active, can again be checked by severing the roots below the pot, wholly or in part, as may be required.
The way to pot the young" tree for this mode of growth is, first to enlarge the hole at the bottom of the pot to the size of three or four inches. Place three or four large pieces of broken pot over this hole, so that there is room for the roots to protrude through in several places. Now place a few pieces of fibrous loam or turf on these broken crocks, and the tree upon that. Then proceed to fill up the pot, compressing the compost with care, but firmly and evenly, as before directed. On account of the rooting into the border, and the increased support there to be derived, smaller pots may be used; but it is not expedient to use a less size than eleven inches in diameter, in which size, if desirable, some kinds of fruit may be grown for three or four years, or even longer.
The border within the house upon which the pots stand should be composed of rich material, such as rough turfy loam mixed with manure from an old hot-bed, forked up and left in a loose, open state, so that air may circulate freely through; and the pots when placed on it will press the surface under them sufficiently to enable the roots to obtain a firm hold beneath.
The best time to pot the plants is in October or November, but it may be done in February. In the fall, the sooner it is done after the leaves turn yellow the better; and they should be immediately pruned. If young trees a year old, cut them down about the sixth bud from the surface of the pot; if a year older, cut each branch (of which there should be left three or five, according to the strength of the plant) to about seven or eight inches in length. Give a good watering, to wet completely through the ball of earth as soon as potted; and water occasionally if necessary, but not otherwise, just to prevent the earth becoming dust dry, until frost sets in. From that time no more water will be required until February. The pots may all be put close together in the house, having a good covering of hay or straw over the whole to keep severe frost from them. Take care mice do not get at the bark.
In February, towards the end of the month, examine the plants, and place them in the border, (if there be one) at least three feet apart, and so that their foliage will not shade one the other. Give each a small quantity of water; and in a week's time give more, so as to bring the earth into a moist state gradually; as to which, the temperature, whether warm or otherwise, must be the guide.
Ventilation, both at front and back or top of the house, will now be necessary all day, and at night also, whenever sharp frost or a cold frosty wind does not prevail, in which case guard against it.
As soon as the buds on the trees commence to break into leaf give them (annually) a good top-dressing of very old stable manure; and also a thorough watering with manure water once in every six or eight days; and except on dull cloudy days, or when frost is severe out of doors, they will require daily a good soaking with soft water, which must never be given of a lower temperature than the atmosphere of the house. The afternoon is the best time to water in hot weather, and the morning in cooler weather.
As soon as fruit has set and is commencing to swell, but not before, syringe the house freely morning and evening, and this should be continued until the period arrives for the fruit to arrive near to maturity. As soon as it begins to change color leave off syringing; but the daily supply of water must be continued until the fruit is gathered, and until the leaves commence to turn yellow. From that time withhold water gradually, and let the plants go to rest.
When the leaves begin to change, such of the pots* as are rooted into the border should have a knife passed under them, and the roots cut off close to the bottom of the pot.
During the growing season the supply of water must be regulated by the state of the weather. It must be borne in mind that where the roots are allowed to ramble in the border, the plants are not so liable to suffer from neglect of watering as are those confined entirely to the pots. And although it is not, on the whole, advisable to plunge the pots, yet it is a good plan to rest a piece of board or something against the side of the pots, standing next the front of the house, to prevent the sun's rays from striking directly against them.
The great thing to be attended to is to give plenty of air. Without ample ventilation it is quite useless to attempt this mode of cultivating fruits. From the time that growth commences in the spring until the fruit is ripe, there should be constant circulation of air through the house; in fact, all that can be given consistently with keeping out frosty or very cold winds; which latter, although not frosty, are injurious.
As regards pruning, the leading shoot of each main branch should be cut back in October, according to its strength: probably from one-half to two-thirds the growth of the year. Besides this, at the end of May or in June, the side shoots that grow upon the main branches must be pinched off, reducing them to an inch in length; two leaves left on each are sufficient. These so left will become future fruit spurs. Where the plants have rooted into the border, their branches should receive their fall pruning at the turn of their leaves, at the same time that their roots are severed, as above directed.
After three or four years' growth in pots, the main branches will diminish considerably in length; and then they require but little shortening in the fall; but the summer pinching of all lateral shoots will be annually required. And when that is done it is also best to pinch the extreme points off the main branches also; but on no account to shorten those until the fall.
When about the size of marbles, the fruit must be thinned, taking care never to overcrop the plants, or their future bearing will be injured. The number left must be regulated by the size of the tree; from one dozen to three or four.
If, when in vigorous growth, any plant that has thrown down roots into the border is found to be growing too luxuriantly, and making elongated, watery wood, it may easily be checked by cutting the roots below the pot partly through, by passing a knife between the bottom of the pot and the surface of the soil on one side only. Where the roots are altogether within the pot, overgrowth is not likely to occur; on the contrary, after growing in the same pot for two years, such plants should be shifted into larger pots or wooden tubs, which latter are the best, because they protect the roots better than earthen pots from changes 'of temperature. When shifted, the surface soil may be taken away with a pointed stick for an inch or two, and the sides slightly pricked with the stick to loose some of the roots; and dead roots, if any at the bottom, should be cut away. In placing in the larger pot, secure good drainage, as in the first instance, and take care to press the compost very firmly between the old ball and the sides of the new pot.
Unless this is well done, the water afterwards given will pass off through the new compost, and the old ball of roots will gradually die and cause the death of the tree.
Those plants which are allowed to root into the borders will not require repotting so often as others. No grape vine or other foliage must be trained over the roof of the house. If a vine is required, it must be confined to an end of the house. No fruit trees would do any good beneath its shade.
[This last caution is a very necessary one. We have seen several attempts to grow fruit trees under vines, but they were signal failures, the fruit, when it ripened at all, being quite insipid and worthless. The best that can be done under such circumstances is to start the trees in a cold vinery, and move them out of doors as soon as the vines begin to make the least shade. The only way in which both can be cultivated in the same house is to grow the trees and vines in pots, and this can be done in a satisfactory manner. - Ed].