A bush fruit tree is one that is allowed or encouraged to form a spreading bushy head near the soil level. A well-formed bush should have several stems radiating from the main stem near to the ground level — generally 18 in. or 2 ft. from the ground, as such bushes are more easily managed. It is difficult to cultivate between bushes that have no clear main stem. In the proper bush type of tree there is no central trunk to the head of the tree, but only radiating branches with an open centre that allows plenty of sunshine to reach all parts of the tree.
A pyramid tree is somewhat similar to the bush type, but in this case the central main trunk is retained, and side shoots spring from this at various points, making a pyramidal silhouette to the tree.
The single-cordon tree is the simplest form of trained tree. In this the growth is restricted to a single main stem, and all side branches are cut away. Properly grown a cordon should be studded closely with blossom and fruit spurs throughout its entire length. Neglect of pruning for a single season will ruin a cordon-trained tree, and no grower should embark on this form of fruit culture unless he can give the necessary small attentions at the right season. The pruning is not difficult, and is an interesting hobby. Moreover, it results in fruit of the finest possible quality, and plenty of it.
Other trained trees are merely variations of the single cordon.
The double or treble cordon is, as the names imply, just a tree with two or three cordons instead of one.
Fan-trained trees are trees grown in a single plane, to train on walls or fences. The cordon-like branches radiate from a point near the ground, fan-wise. Espalier trees are trees with an upright central stem and side branches at regular intervals trained horizontally, giving the effect of a double staircase.
Most fruits can be grown in any of these ways, but the slightly tender fruits that need warm sunshine to ripen them, such as nectarines, apricots and peaches, are generally best as wall-trained trees on a south wall, since this gives them a warm situation. Cherries, except the Morello cherry, are not very suitable for wall culture, and stone fruits generally are better grown as fans than espalier trained. The Morello cherry does very well indeed on the north side of a wall.
Before turning to the details of culture of each fruit, it is worth while to mention a point which affects chiefly the grower of a single specimen tree. Certain varieties of various fruits are not self-fertile. That is to say, if they are grown by themselves, and not near to any other fruit trees whose blossom is open at the same time, they do not set their fruit, the reason being that the pollen from their own flowers will not fertilize the waiting stigma. They require pollen from some other different tree and in some cases only certain varieties will cross-pollinate successfully. Cherries are particularly difficult in this matter, and the Morello (cooking) cherry is the only variety that is completely self-fertile. Sweet cherries should only be planted where they can be planted in pairs, or where a neighbour grows cherries too. In districts where a good deaf of fruit is grown this difficulty does not often arise, but in thickly populated areas, where perhaps only a few isolated fruit gardens exist, care should be taken over selection. Any fruit grower will advise on this point as far as he is able (full statistics on every variety are not available), and will suggest trees that are self-fertile for specimen planting.
Fruit trees are deciduous trees, and the planting season is therefore at any time from about October until March. Early winter is certainly the best time, as the roots can establish themselves during the resting season. It is sometimes thought that roots are not active during the frosty weather, but this has been proved wrong. Plants grow a little even under a mantle of snow, and when frosts do not penetrate far into the soil, the roots are active even though there is little visible top growth. Planting a new orchard should thus be regarded as an October or November task.