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 out weak, crossing, or crowded stems
Trim spent flower heads if needed
Make cuts just above a healthy bud or pair of buds
Use clean, sharp pruning shears
Avoid heavy pruning on old wood bloomers
Reduce stem length only as needed to shape the plant
Remove no more than one-third of the plant at a time
Clean up all cut material after pruning