UC Davis on early shaping/pruning of fruit trees

http://cekern.ucdavis.edu/Master_Gardener/Planting_and_Early_Care_of_Deciduous_Fruit_Trees.htm

Unlike shade trees, deciduous fruit trees should be pruned every year before bud swell for optimum growth and yield. Pruning need not be complicated, but fruit trees are less forgiving than most shade tree species, and with incorrect pruning the yield of fruit will be reduced or eliminated, and the life of the tree will be shortened.








There are three pruning phases in the life of a deciduous fruit tree. The first occurs at planting, when the first cut should be made to foster development of a vase-shaped structure, since an open-center form is preferred for almost all deciduous fruit species on the San Joaquin Valley floor. After a bareroot tree is planted, the trunk should be headed at 24-32 inches above the soil surface. This cut may be emotionally difficult to make, because it may seem $10 of a $15 tree has been summarily removed. In reality, this most-important cut serves to establish low origination points of structural branches, which will allow most pruning, harvesting, and pest management to be performed without a ladder during the life of the tree. When we purchase a tree at the nursery, we are paying for a well-developed root system and the top (scion) variety. The upper structure of the tree may induce purchase by the buyer, but should be removed upon planting. Trees in agricultural fields need higher heads for equipment passage, but at home a low head greatly facilitates tree care.







The second phase of pruning serves to establish structure, and this phase begins the year following establishment. The low heading cut will result in several branches growing outward at various directions and angles, and three or four strong, upwardly growing branches spaced at intervals around the trunk should be selected as scaffolds. Additional branches can be removed. Pruning the next few years emphasizes structural development, including a well-spaced system of scaffolds and laterals.







The third phase of pruning begins with the onset of maturity, which is 5 - 7 years for most fruit trees. At this stage, the tree should be pruned for fruit production, with consideration of the location of fruiting wood. Pruning at this stage serves to invigorate and direct growth of the tree, with a goal of keeping it forever young; that is, annually producing new fruiting wood. Deciduous fruits differ greatly in the amount and location of wood which should be removed. Of trees often found in home orchards, peaches should be pruned the most severely and cherries the least. A detailed discussion is beyond the scope of this article, but principal determinants for pruning are the location and amount of fruiting wood. For example, peaches bear fruit on terminal wood of the previous season, so well-spaced lateral shoots with flower buds are retained. For peaches, it is common to thin (remove) half to two-thirds of the laterals, and to head (shorten) remaining fruiting wood. Apricots, plums and sweet cherries bear fruit laterally on spurs, which live three, five, and ten years, respectively. Therefore, up to 1/3 of the wood may be removed in mature apricots, about 1/5 of the wood in plums, and only light annual pruning is needed for sweet cherries.