Most routine pruning and removal of weak, diseased, undesirable or dead limbs can be accomplished at any time with little negative effect on the tree's overall health.
As a rule, growth is maximized if pruning is done just before the buds swell, in late winter or early spring. Pruning when trees are dormant can minimize the risk of pest problems associated with wound entry and allows trees to take advantage of the full growing season to close wounds.
Plant growth can be reduced if pruning takes place during or soon after the initial growth flush. Removal of many live branches at this time can stress the tree.
Trees that bloom on current season's growth are best pruned in winter, prior to leaf emergence, or in the summer after bloom has occurred.
Trees that bloom on last season's wood, such as many fruit trees, should be pruned just after bloom.