Crown Reduction Use crown reduction pruning only when absolutely necessary. Make the pruning cut at a lateral branch that is at least one-third the diameter of the stem to be removed. If it is necessary to remove more than half of the foliage from a branch, remove the entire branch. Branches are cut back to laterals that are at least one-third the diameter of the limb being removed. Trees with this form have several to many lateral branches that compete with the central stem for dominance resulting in a spherical or globose crown.
Most hardwood trees have decurrent forms.
In older wood, epicormic shoots often result from severe defoliation or radical pruning. Trees with this form have a strong central stem and pyramidal shape. Lateral branches rarely compete for dominance. Most conifers and a few hardwoods, such as sweetgum and tuliptree, have excurrent forms. Topping is often improperly referred to as pollarding.