What is the best time to prune a viburnum? And how much should I prune? —Clarence Hyde, McDonough, GA
Gardeners grow many varieties of viburnums—most of them for their showy flowers. Some blooms are even sweetly scented. When and how much you prune depends on the type of viburnum you’re growing and its purpose in the landscape. If you want to enjoy the flowers, prune immediately after the flowers fade. If the flowers are unimportant, prune in late winter or early spring, just as the plants are coming out of dormancy.
The natural shape of the plant is usually most attractive, so keep your pruning to a minimum. Remove broken or unattractive stems and old, thick stems that don’t bloom as well as younger ones. Once the shrub matures, prune some of the oldest stems back to the ground every year or so. Never remove more than one third of the stems at one time.