Prune fruit trees annually during the dormant season, which is in the winter or early spring for most types of fruit trees, especially pome trees such as apple or pear trees. Prune late in the winter after the danger of freezing damage is past, but before the growing season begins in the spring. It is best to prune when the buds first appear so that branches can be pruned just above the buds. However, for the stone fruits such as peaches, cherries and plums, prune around August, just before the dormant season begins and right after the final harvest, to prevent blight.
Pruning for Good Hygiene
One reason to prune the fruit trees every year is to keep it healthy and productive. Use a pair of long-handled pruning shears with good, sharp blades to make a clean cut that will heal well. Make a backward 30-degree cut just above a joint or a bud, or right at its base against the trunk or main branch. Do not leave a stub of a branch. Use pruning shears for smaller cuts and a pruning saw for very large cuts. Prune off any dead or diseased limbs, and any injured or broken limbs. Prune branches which rub against and cross each other. Prune branches near the center of the tree around the central trunk so that the foliage will not be too dense to allow light to all the branches of the tree. Do not remove more than 30 percent of the branches in any one year. After pruning, remove leaves and other debris from the ground under and around the tree as that can rot and breed spores and pests which would cause disease to the fruit tree.
Shaping the Young Fruit Tree
The main goal of pruning for the first five years is to form a framework on which the fruit will grow once the tree starts producing. The desired shape of the tree depends on the type and variety of the fruit. Depending on the shape the tree is to have, all shoots off the main trunk except those which are desired for the upward leader and/or the lateral main branches. Depending on type of tree, leave a central leader (a single upward growing branch or extension of the main trunk), or about 3-4 lateral branches, or both. The trees needing a central leader are apple, pear, and sweet cherry. The types of trees to be pruned with 3-4 lateral branches with branches from these main branches are: Plum, nectarine, peach, and sour cherry. Nut trees can have both a central leader and a few main lateral branches.
Training up a Tree in the Way It Should Grow
The upward main branch, called the central leader, should have no lateral shoots along its length down to the first scaffold of branches. A scaffold is a set of four main lateral branches originating from near the same point on the main trunk, radiating outward in all directions from the trunk. The first scaffold is chosen and left when the young tree is pruned of other shoots after the first year, and as the tree grows in height in succeeding years, more scaffolds are allowed to grow from the trunk, in such a way that 18 to 24 inches of bare trunk provide light slots that separate the scaffolds. The ends of the central leader and the lateral branches should be pruned so that the main branches of the lower scaffolds are longer than those of higher scaffolds, to permit sunlight to the lower branches. The central leader should be pruned to limit the height of the tree, no more than 6 to 12 feet, as a tree that is too tall will produce fruit that is too high to be harvested. The lowest scaffold should be about 24 to 36 inches from the soil surface, so that the lowest branches will be high enough off the ground that they can be picked easily from beneath them. If an open center tree, rather than a central leader, is mandated for the type of fruit tree, the central leader can be pruned gradually shorter in successive years until only the lateral main branches remain, or the central leader can be pruned so that only lateral branches remain.
Stimulating Fruit Production
The fruit bearing branches of trees that are old enough to produce fruit should be pruned of unnecessary growth that will divert nutrition from the fruit-bearing branches. If the tree is not pruned or too lightly pruned, too much foliage will take away nutrition from the flowers and fruit so that the fruit will be too small and undeveloped. However, overpruning will cause the fruit to grow too heavy and cause the branches to break. Fruit production will also start earlier if the lateral branches are spread to a wide angle from the trunk by spreaders, which are 1-inch pieces of wood of lengths varying from 6 to 12 inches. Branches that extend vertically up and down from the main branches should be pruned, so that the remaining shoots and branches will grow horizontally from the sides of the branches. Suckers, or unwanted shoots off of the main trunk, central leader and base of the tree should be pruned.