Annabelle hydrangea is a deciduous shrub that produces large white blooms in the summer. The blooms are suitable for cuttings for floral arrangements or for drying. Annabelle hydrangeas do not require pruning unless you want to control how large the shrub gets. Pruning Annabelle becomes a guilt-free effort since the shrub blooms on new wood, unlike the pink and blue macrophyllas, or mophead variety, of hydrangea that blooms on old wood (prior year's stems).
Cut out broken stems anytime during the growing season. Make an angle cut 6 inches away from the break.
Prune to shape from late fall to early spring. Annabelle hydrangea blooms on new growth so prune while the shrub is dormant. Prune spent blooms anytime.
Make cuts on an angle immediately above a bud or set of leaves.
Prune an overgrown Annabelle hydrangea 10 to 12 inches above ground. Cutting any shorter could result in weak stems that might not be able to support blooms.