Generally speaking, fruit trees (apples, pears, cherries, etc.) are pruned in late winter or early spring, That’s because they’re full of energy at that season, ready to burst into glorious bloom, and will react to pruning by growing back vigorously. And you want fruit trees to be vigorous. But there are cases where you don’t want regrowth … and that’s where summer pruning comes in.
Pruning in summer reduces the vigor of the branches removed and is used to permanently repress unwanted suckers, watersprouts and other undesirable growth.
Watersprouts are the thin branches that grow straight up. They often appear from the trunk or from secondary branches. They produce neither flowers nor fruit, but just take up space and use minerals that could go to productive branches. You just have to cut them off at the base, as close as possible to the trunk or the branch they grow from. Removing them in summer rather than spring will help keep them from regrowing.
Suckers are branches that grow from the base of the tree or from its roots, sometimes a certain distance from the mother tree. Like watersprouts, they produce neither flowers nor fruit, at least not for many years, and take up valuable space and minerals. There is no reason to keep them. In fact, since they inevitably sprout from below the graft point (you did know your tree was grafted, right?), if ever they did bloom, they wouldn’t even produce fruit of the right variety! (A sucker from a cultivated plum with big fruits, for example, would likely give small-fruited wild plums.) By pruning in summer, you’ll help discourage the tree from producing more of them.
Always remember that, to avoid spreading diseases, it is best to prune fruit trees on a dry day and to dip your pruning shears into rubbing alcohol between each cut.
Finally, if there are any other branches you want to permanently remove without stimulating the growth of replacement branches, summer is the best time to do so.
Summer pruning: it’s quick, easy and pays off in the long run!