Pruning your bosc pear is a matter of shape as well as good air circulation. As your tree ages, your pruning techniques will change somewhat, although some things will remain the same. You always want to trim branches that are growing too close together, and you always want to remove all old fruit and any diseased or dead wood. Always rake up and discard old fruit to prevent potential tree diseases.
Perform major pruning in late winter. Prune very sparingly in the summer months. Remove any root suckers as soon as they appear, usually during summer.
Cut all dead and diseased branches first. Remove any old fruit that is still in the tree.
Step back and look at your tree. Decide which branches must be trimmed for your tree to cast a nice appearance and to be balanced. Remove branches that do not add to the tree's shape or balance. Branches may be cut near the ends to create shape or may be cut next to the trunk. Leave three to four horizontal branches below the primary up-thrusting branches.
Cut back the main up-thrusting leader branches, leaving approximately 25 inches of each branch.
Remove all branches that have a narrow branching angle that is blocking sunlight and air flow to the interior of the tree.
Cut back all new growth from the previous summer to approximately 30 inches.