Those who are used to seeing large fruit trees in orchard plantations where each specimen has 1,000 to 2,000 square feet of space, with unlimited opportunities downward, find a fruit tree in a pot a curiosity. It seems remarkable to see a tree in vigorous health and bearing fruit with less than one cubic foot of soil. Nevertheless this method of handling fruit trees is entirely practicable. In some places it is practised extensively in an amateur way, and occasionally reaches almost commercial proportions. For those who grow fruit trees for recreation there could hardly be a more interesting experiment.

The pots mostly used are the nine, ten, eleven and twelve inch standard earthenware pots. With most trees it is best to begin with small sizes and gradually shift forward to the larger ones. A bearing tree may be maintained for several years in a twelve inch pot or even in a ten inch size. Sometimes wooden tubs are substituted for pots. These look better, but are not so good in any other way.

Trees may be grown in pots out of doors, although there is no particular advantage in doing this. If such practise is undertaken the pots should be plunged their full depth in good garden soil. Perfect drainage should be secured by having some broken brick or coarse cinders underneath.

Usually potted trees are grown under glass. They are kept in a cool greenhouse, that is one with little heat. Sometimes they are without artificial heat. In fact this is probably the best way. The houses which are purposely constructed for fruit trees may have a single line of pipe if this is convenient, so that the chill may be taken off the air in severe cold weather. To reach anything like real success, houses must be devoted exclusively to fruit trees. Occasionally trees may be grown with other plants, as in cold graperies, but the results are not the best and often come very close to failure.

In building houses for fruit trees exclusively, the even span construction is nearly always used. Houses eighteen or twenty feet wide, and five feet high at the eaves, will answer the purpose very well. The leading greenhouse designers are prepared to furnish plans for such houses and it is usually best to follow the advice of their experts.

All kinds of fruit trees can be grown in pots. This includes apples, pears, peaches, plums, nectarines, and cherries. Those which give the best returns are plums and nectarines. Apples in pots are very interesting and furnish a superior quality of fruit when grown under glass. Apples, plums and nectarines take a finer finish and a higher flavor when grown in this way than when grown in any other.

All fruit trees to be grown in pots should be propagated on the dwarfest of dwarfing stocks. This means practically that apples should be on Paradise, pears on quince, peaches and nectarines on sand cherry, plum on sand cherry or St. Julien plum, and cherries on Mahaleb.

The trees should be potted in good rich soil, preferably the best garden loam. This should have enough sand and gravel in it to insure good drainage. A considerable amount of drainage material should be placed in the bottom of each pot. The trees should be repotted in fresh soil annually in October or November.

Trees in pots require liberal feeding. Besides being given well enriched earth at the time of repotting, they should be supplied from time to time with small amounts of fertilizer. Good soluble chemical fertilizers can be applied either dry or dissolved. A good formula is one part nitrate of soda, two parts of muriate of potash, two parts of high grade phosphoric acid. A very little sprinkling, say a tablespoonful, of this can be given on each pot once a month during the growing season which lasts roughly from December to May. In place of this, or alternately with this, moderate waterings with liquid manure may also be given. These small doses of food are especially useful at the time when the fruit is forming on the trees.

The trees are usually brought into the house at the time of potting, say November 1. If early fruit is desired, they are kept in a house with some heat. It is necessary only that the temperature should be kept constantly and safely above the freezing point. Rapid forcing with a high temperature is not desirable and is hardly possible. If kept simply above the freezing point, these trees will start into growth in January. They can then be kept somewhat warmer during February, the heat being slightly increased in March. Peaches and nectarines will stand fairly high temperatures after the fruit is well set and especially toward ripening time. By this method of mild forcing, plums, peaches, and nectarines can be brought into fruit as early as the latter part of May.

FIG. 42—A FIG TREE IN A POT