Prune a burning bush shrub in early spring to ensure time for new growth to develop and to minimize the risk of damage to tender shoots from harsh winter temperatures. Trim each limb at a 45-degree angle to allow water to run off easily, and shape the bush throughout the growing season to maintain its appearance and size.
A burning bush grows slowly, but can outgrow the original space without pruning. Light, routine prunings are necessary to maintain the size and shape of the bush, while a heavy pruning rejuvenates straggly limbs. Cut out dead or diseased limbs as needed, and trim the top of the bush to a slightly narrower shape than the bottom to allow light to reach the interior of the shrub. Cut the bush to within 3 inches of the ground to regrow the limbs.
Burning bushes are hardy shrubs that can grow from 9 to 12 feet tall with a circumference equal to the height. The leafy green foliage turns bright red in the fall, providing an attractive display for home landscapes. The burning bush thrives in U.S. Department of Agriculture Zones 4 through 8 and is often used in flower borders, beds and containers.