Hydrangeas in Arkansas
Hydrangeas are an important group of ornamental flowering shrubs that offers something for sun or shade gardens. While most of us think of Hydrangeas as great shrubs for the shade (e.g. Bigleaf Hydrangea and Oakleaf Hydrangea), the Panicle Hydrangea (H. paniculata) is a great option for a sunny location.
Pruning is always a tricky question with Hydrangeas. Panicle (H. paniculata) and Smooth Hydrangea (H. arborescens) flower on NEW wood (just like a crapemyrtle) so they can be cut back immediately after flowering and may rebloom later in the season, or, they can be cut back in the winter and still be expected to flower the following year.
The next group which includes Bigleaf Hydrangea (H. macrophylla) and Oakleaf Hydrangea (H. quercifolia) are alleged to flower on buds that were formed the previous season. Therefore, if you prune them in late fall to early spring, you will sacrifice that season's flowers. If the plant requires significant pruning, do it immediately after flowering.
Thanks to Joel Stout, Cricket Hill Farm, Conway, Arkansas for his input.
Dr. Jim Robbins, Extension Horticultural Specialist - Ornamentals