When Does Hydrangeas’ Aged Wood Cease Growing?

Hydrangeas bloom on old wood, stems produced on the previous year’s growth, making them sensitive to harsh winters. Old wood hydrangeas bloom on the previous year’s growth, while new wood hydrangeas bloom on the current growth. Some hydrangeas bloom on old wood, which is produced on the previous year’s growth and generally bloom in early summer. They should be pruned in late summer, after flowering, or no later than August 1. The best time to prune old wood hydrangeas is after they have flowered and no later than August 1.

Pruning time depends on whether hydrangeas bloom on old or new wood. Old wood bloomers should be pruned after flowering in late summer, while new wood bloomers should be pruned in late winter or early spring. Proper pruning depends on whether the hydrangea blooms on old or new wood. If your hydrangea blooms on “old” wood, do not cut back in the fall or sacrifice next year’s flowers. Most pruning is carried out in late winter or early spring. Climbing hydrangeas are pruned after flowering in summer, while those that bloom on new wood can be safely pruned in late fall once the plants have gone dormant or in early spring.

To rejuvenate the hydrangea, leave all of them alone in the Hydrangea Danger Zone (HDZ) between August 1 and when buds appear. “Old wood” means that buds for next year’s bloom are formed on stems produced during the current growing season. Bigleaf, oakleaf, climbing, and mountain hydrangeas bloom on old wood and can be pruned immediately after they finish blooming before pushing them out.