Identify the hydrangea type before pruning
Prune bigleaf, oakleaf, mountain, and climbing hydrangeas right after flowering
Prune panicle and smooth hydrangeas in late winter or early spring
Remove dead, damaged, or diseased stems first
Cut spent flower heads just above the first pair of healthy buds
Thin out weak or crossing stems at the base
Reduce overgrown stems by cutting back to a healthy set of buds
Avoid heavy pruning on old wood bloomers
Use clean, sharp pruning shears
Disinfect tools between plants
Stop pruning after late summer for old wood bloomers
Remove only light growth from established plants if unsure of the type