The pruning of fruit trees is often thought of as mainly a wintertime activity, but orchard experts now suggest pruning should take place all year round. Trees respond differently to dormant and summer pruning. Dormant pruning invigorates the tree. Removing a portion of the tree in the winter, when the sap has gone into the roots, keeps the tree’s energy stores intact. While dormant pruning helps promote the desired tree shape, it results in a wild growth of new shoots in spring that can shade the tree and inhibit the development of fruit.
Summer pruning, on the other hand, reduces a tree’s energy reserves by taking away leaves that contribute to growth. It opens the tree to light, producing bigger, healthier fruit. Summer pruning is not a way of controlling the tree’s size. That is the job of dormant pruning.
Summer pruning requires a good set of secateurs (pruning clippers) and should be done using the whole blade rather than just the tip that may snag or tear a branch.
The goal is to remove the season’s new growth by cutting off the basal cluster, the whirl of leaves at the end of a new shoot protruding from the old wood. Cut through the branch about ¼ inch above the basal cluster at an angle slanting away from the tree. New growth from the cut will thus be directed away from the tree. Prune any branches that are blocking light from the forming fruit. Opening up the canopy also allows better air flow through the tree, promoting rapid drying that minimizes disease and allows better penetration of pesticides. The light penetration also promotes the growth of flower buds that will set fruit in the next year’s growing season.
You can summer prune from eight months after blooming until mid August. Overall, summer pruning will slow the growth of a tree by reducing its root growth, helping keep dwarf trees a manageable size.
After summer pruning, thin out the fruit. Leave a hand’s width between young fruits, and reduce clusters of fruits to just one. Also eliminate any fruit that has been damaged.
When a tree is very young, you can achieve a good open shape by using 1-inch square wooden spreaders with nails in each end to keep lateral branches growing at an open angle. A fruit tree should be wide open enough in the middle for a bird to fly through without hitting the branches.