SHADE TREE PRUNING TIPS
Shade trees should be pruned and cared for much the same as fruit trees.
Pruning at Planting - Trees with the roots balled and wrapped in burlap or plastic need little pruning when planted. Remove any crossing branches or growth that will not be part of the tree’s framework. Container grown trees usually need no pruning. Remove any dead or broken branches. Bare-root trees usually require some pruning to eliminate any broken roots before planting. You may want to cut back the main stem to encourage branching and balance branches with the remaining roots.
Young shade trees should be trained in the same branch patterns as fruit trees while preserving the natural habits of that tree. Pin oaks, birches, poplars and similar types usually grow a single central leader with well defined side branches. If they form more than one leader, remove the weaker ones. Remove branches that form a deep V-shaped crotch because they are vulnerable to wind damage, breakage and rotting. Wide crotch angles are stronger. As with fruit trees, central leader or modified central leader forms make the strongest trees.
Mature shade trees are best left alone except for the removal of dead, injured or diseased limbs. Thin out branches if they become too dense.
Outside of emergency operations, it is not wise to prune shade trees during the period when sap is flowing. Some trees such as birches, elms and maples bleed freely when pruned during this period. Prune trees of this type as well as willows, oak, ashes and sycamores in summer after leaves have developed.
Ornamental trees grow in the same manner and shapes as shade trees. Once mature they should need only maintenance pruning. Follow the same rules for pruning at planting time as with fruit or shade trees. Usually flowering trees are trained in the central leader form. The best time to prune most flowering trees is just after the blossoms fade. If they are a type with colorful berries, you want to leave on the tree, prune in late winter. Avoid letting them ramble and grow like shrubs instead of trees.