You can prune eastern redbud trees once or twice a year. The best time is immediately following the spring blooming period, generally in April or May. The second pruning can be late winter before the tree begins to leaf or bud. For best results, prune to control shape and size when the tree is young and small. Because the branches are small, the cuts are small, leaving less area open to infestation by insects or fungi. For older trees that need shaping, never cut more than 25 percent of the tree during one annual pruning. Intense pruning will remove too many leaves, which the tree uses to produce food, and it may become dwarfed.
Evaluate the size, shape and natural growth of the tree. Because eastern redbuds tend to have multiple trunks, determine which are the sturdiest and give the best overall shape to the tree.
Place a ladder under the tree to reach upper sections. Secure the base of the ladder against something sturdy; the top of the ladder should lean against the trunk with sturdy branches to either side to prevent slipping. If branches are not available, you can tie the ladder in place. Pinch off new growth at the tips to control the size of the tree.
Amputate any damaged, diseased or dead branches, using hand shears for branches under 1 inch in diameter. Use lopping shears or a pruning saw for larger branches.
Trim any crossing or rubbing branches to prevent damage to the limbs that can result in insect or fungi penetration. Use a pole pruner to reach parts of the tree you cannot safely prune from the ladder. Lift the pole pruner to the desired branch, positioning the jaws around the branch to be cut. Pull down on the rope, closing the jaws and cutting the branch.
Make smooth cuts that leave no stub. Leave the collars of branches intact because a cut too close to the trunk can damage the tree.
View the tree from a distance of 10 to 15 feet to determine if the branches have approximately 2 feet of vertical space between them. That space allows adequate sunlight and air circulation to lower limbs. Make any "heading back" or trimming cuts about a quarter-inch above a bud or lateral branch.