Winter pruning is meant to stimulate the tree. Summer pruning uses thinning cuts (where the branch is cut off at its point of attachment, instead of part way along the branch) and these cuts do not encourage new growth. By removing leaves with the limbs, the tree is also getting less energy.
Summer pruning is a technique to train young fruit trees, with thinning cuts to build your ideal tree limb structure. If you want to keep your mature fruit trees at an easy-to-harvest height, summer pruning is essential.
Apricots and plums grow more slowly and only need to have 20% of their new growth pruned away.
Experts differ on summer pruning of cherry trees. Mario Moratorio, former Farm Advisor in El Dorado County, suggested summer pruning cherry trees only for the first five years. Chuck Ingels, Sacramento County’s Farm Advisor, recommends pruning 10% off mature cherry trees.