Interest is once again revitalized in the art of summer pruning fruit trees. Summer pruning is simply refers to the time of year pruning is performed — when trees have foliage — and does not describe the type of pruning cuts, pruning severity, or the physiological stage of tree development when pruning is performed.
It is believed that summer pruning promotes reproductive growth and dormant pruning promotes vegetative growth. However, results from controlled experiments performed during the 1920s and the 1980s did not support this assumption and summer pruning has never been recommended for commercial orchards. Exceptions include removing excess shoot growth to enhance light distribution in the tree to improve red fruit color and to retain fruiting wood in the interior of vigorous peach trees.
To read more about the benefits of summer pruning, click here.
Source: Penn State University bulletin