When to Cut Back Hydrangeas & Crepe Myrtles

Time Frame

• Prune crape myrtles, both tree and dwarf shrub forms, in very early spring just before the buds swell and new leaves emerge. Prune away dead or broken branches any time of year. Hydrangea pruning time varies by species. Prune mophead or lacecap hydrangeas (Hydrangea macrophylla) in early summer immediately after flowering ends. Prune other common garden species, like Hydrangea paniculata and Hydrangea arborescens, in very early spring.

Effects

• Pruning not only removes dead and broken branches and leaves, but also causes dormant buds to sprout and rejuvenate plants. Crape myrtles produce new growth that flowers later that year in summer. Mophead/lacecap hydrangeas produce flowers from buds that matured the previous autumn; that's why you should not prune them before they bloom. Other species of hydrangeas produce flowers on new growth later that summer, but don't over-prune them.

Prevention/Solution

• Severe topping of crape myrtle trees reveals the gardener's or landscaper's lack of training, creating skeletal tree silhouettes colloquially called "crape murder." This bad practice, according to Virginia Cooperative Extension, harms the tree, ruins its structural integrity and does not result in more flower heads when compared to a more lightly trimmed tree. Only prune crape myrtle branches that are less than 1/4 inch in diameter to maintain a nicely shaped tree. Dwarf, shrub-like crape myrtles, however, should be cut back to the ground each early spring to rejuvenate.