The stone fruits are superior (33. Inferior and Superior Flowers) and more liable to injury of blossoms by late frosts than the apple or pear. Hence the most profitable and regular bearing orchards of cherry, plum, prune, apricot, and peach are found where proximity to water lessens liability to damaging frosts in the blossoming period, or on relatively high land with good air-drainage (97. Air-drainage). But it often happens that relatively low land has still lower levels of large extent in the near vicinity and may prove as free from frost as decided ridges.
Budded trees on strong stocks usually are large enough for orchard-planting when one year old. But crown-grafted trees should remain in nursery until two years old. The distance apart and plan of planting are discussed in sections (115. Distance Apart of Peach, Plum, and Cherry) and (117. Fall- or Spring-planting), and the alternating of varieties in the row to secure proper pollination in section (122. Alternating Varieties in the Rows).
Pruning (147 and 148) varies much in different climates and with different varieties. The native plums usually require but little pruning, and that in the way of shortening rampant-growing shoots prior to the trees coming into bearing. When fruiting heavily the main essential in pruning is the cutting out of dead wood in the interior as it appears. The select native varieties are rapidly taking a place in the leading markets, but their habit of overbearing requires thinning if the best prices are to be realized. In. California, and on rich soils in the South and East, the domestica varieties make too rapid growth when young. To secure the needed thickness of top to prevent the sun-burning of the wood and fruit they are headed back (148. Pruning the Cherry and Plum), causing a subdivision of the growing wood. As the trees get older less pruning is done, confining it mainly to the removal of dead wood and shortening the young shoots making greatest length, to prevent unequal growth and to lessen the amount of bearing wood.
The domestica plums and the apricot seem to bear excessive cutting back of the top. In California and the South the low stem is now the rule, and when first set out the stems are protected by burlap or whitewashing. But on very rich lands a kind of renewal system is adopted with the tops. As an instance, in the San Joaquin valley on the west coast the tops of young plum-trees and even apricots are not cut back. The long shoots formed are thinned to some extent and encouraged to bend over. These when loaded with fruit rest their points on the ground. When these long canes droop too low they are cut back to the main stem and others take their place for the succeeding crop. But trees worked in this way are not as long lived as those on higher land pruned in a sensible way. The pruning of the peach and apricot in the commercial centres is often excessive (149. Pruning the Peach and Apricot), but amateurs in the Middle States usually go to the other extreme by mainly leaving Nature to have her own way.
With few exceptions, growing out of soil conditions and climate, Downing's instructions as given in (149. Pruning the Peach and Apricot) will apply well to-day in amateur peach- and apricot-growing, but not in commercial centres, as the shortening of all new growth gives more trouble and expense after the trees are in bearing than the rougher plan of thinning by cutting out superfluous branches.
Where winter-killing of the new wood is liable to occur, the pruning is deferred until the buds start in spring, and the thinning is confined in the unfavorable seasons to the injured wood, being careful not to injure the live buds.