Hydrangea Pruning Checker
Check old wood, new wood, and reblooming hydrangea pruning without guessing from a white flower alone.
Use the interactive controls to check your conditions. The guidance and sources below are available without the calculator.
The Short Answer
Identify the hydrangea before choosing a pruning season. Maryland Extension groups bigleaf, mountain, and oakleaf hydrangeas as old wood bloomers, and smooth and panicle hydrangeas as new wood bloomers. Confirmed reblooming bigleaf and mountain varieties flower on both. Extensive or regular pruning is not required.
Check the identity first
Oak-shaped leaves identify oakleaf hydrangea. Among commonly grown hydrangeas, blue or purple flowers occur only on bigleaf and mountain types. Both smooth and bigleaf types can have rounded mophead blooms, so a round white flower is not enough for a firm identification. A plant label or the illustrated Maryland guide is a better next step when clues conflict.
Old wood: just after flowering
Bigleaf, mountain, and oakleaf hydrangeas form next year's flower buds during summer and autumn. Prune just after flowers fade if pruning is needed. Maryland allows bigleaf and mountain plants to be trimmed to about 12 inches, and oakleaf to the same height or taller. This is an option, not an annual requirement; removing old wood can sacrifice flowers.
New wood: late winter or early spring
Smooth and panicle hydrangeas form flower buds on the current season's growth. Prune in late winter or early spring. Maryland allows smooth hydrangeas to be trimmed to about 12 inches; panicles may be kept at that height or taller. Do not cut down the trunk of a tree-form panicle unless you intend to turn it back into a shrub.
Rebloomers: preserve as much wood as possible
For confirmed reblooming bigleaf or mountain cultivars, Maryland permits early spring pruning or pruning after the first flush fades. Early pruning delays the start of bloom. Mid-season pruning may interrupt or shorten rebloom. Remove as little wood as possible to avoid delaying new flowers. Do not assume a plant reblooms just because it is bigleaf.
Dead tips and faded flowers
Wait until spring growth reveals dead stem tips, then remove them. Deadheading means removing only the spent flower at a branch tip, not shortening the branch farther down. It is optional and can be done after flowers fade on any type. If identity is uncertain, do not choose a hard cutback from this checker.