Late winter is the time to prune some trees and shrubs. One shrub that perplexes many gardeners is the hydrangea. With many different types of hydrangeas available that bloom and grow differently, it's easy to get confused about when and how to prune. Let me give you some tips on pruning three common types of hydrangeas.
A very familiar type is the smooth leaf hydrangea or Hydrangea arborescens. This hydrangea is often known by its most common cultivar Annabelle. It blooms early to mid summer with white or pink flowers depending on the variety. Smooth leaf hydrangeas bloom on the tips of new branches, so prune it now down to the ground or about 1 foot tall to stimulate new growth for more flowers.
The big leaf, or blue hydrangea, Hydrangea macrophylla, is stunning. It comes in a mophead or lacecap form with brilliant blue, red or pink flowers, depending on the soil's acidity, that open from mid-summer through fall.
Newer varieties of this type of hydrangea bloom on old branches that survive the winter and new branches that grow in spring. The best time to prune is after the first flush of flowers in mid-summer. Prune just to reduce crowding or crossing branches and to remove old flowers.
The panicle or Hydrangea paniculata is a common shrub or small tree form of hydrangea. It has white, red, or pink flowers. It blooms in late summer and fall. Like the smooth leaf hydrangea, it blooms on new growth from the spring, so prune now to shape the plant, remove crowded branches and stimulate new growth that will eventually flower.
