The white ash tree is a popular hardwood. It requires regular maintenance and pruning to promote healthy, stable structures. Neglected or improperly pruned white ash trees are subject to disease, pests and breakage.
Cut stems and small branches of young trees a quarter inch above the bud using hand pruners. Force new branches to grow outward by leaving buds facing that direction. Encourage branches to develop in a staggered pattern by leaving every other bud on each side of the leader (main branch/trunk).
Developing trees sprout multiple leaders. Remove additional leaders as they develop. Cut new leaders at the base of the branch to discourage future growth. Coat with latex wound sealant to protect the tree from pests and diseases. Remove branches that are growing upright to promote straight outward branch growth.
Make multiple cuts into large branches using pruning saw or pole pruners. Make one cut 1 1/2 feet from the trunk on the bottom of the branch, cutting half way through the branch. The next cut should be several inches above the first, cut all the way through the branch. Make the next cut flush with the branch collar, the swollen area along the tree trunk.