Not every hydrangea requires yearly pruning. Old wood bloomers, such as bigleaf hydrangeas, do better with very little cutting -- simply deadhead the spent flowers, and leave the stems intact. One of my clients had a mountain hydrangea, and I spared it from heavy pruning, allowing its cascading blooms to be preserved. Your shears ought to cooperate with the plant's habit.
Old Wood Varieties
- Deadhead after blooms fade in summer
- Remove only dead/damaged stems in spring
- Avoid cutting healthy green wood
New Wood Varieties
- Annual late winter pruning shapes plants
- Cut panicle hydrangeas back by one-third
- Hard prune smooth hydrangeas to 12"
"Reblooming hybrids" (e.g. Endless Summer) redefine the rules: cut first blooms in June to provoke a second bloom, but don't remove fall buds that are left from last year. Last August I had a client remove 30% of finished blooms, their hydrangeas bloomed through November's frost. Precision is better than over kill.
Read the full article: When to Prune Hydrangeas: A Step-by-Step Guide
