How and when you prune your hydrangeas depends on two things: which type of hydrangea you have and whether it blooms on old or new wood. If you’re not sure which type you have, don’t worry, we spell it out for you in the questions above. Here’s how to prune each type:
Bigleaf hydrangeas (H. macrophylla): avoid pruning bigleaf hydrangeas, as they bloom on old wood, which means pruning it will cut off next year’s flower buds. You can trim off any dead wood or old blooms, but nothing more!
Mountain hydrangeas (H. serrata): don’t prune mountain hydrangeas. Similar to bigleaf hydrangeas, they bloom on old wood. For maximum flower power, avoid trimming any part of the plant, except for dead branches and spent flowers.
Smooth hydrangeas (H. arborescens): prune smooth hydrangeas in late winter or early spring by cutting back 1/3 of their total height. They bloom on new wood, so this will encourage lots of new growth, which means lots of flowers.
Oakleaf hydrangeas (H. quercifolia): avoid pruning oakleaf hydrangeas, as it will remove the flower buds for the upcoming season. It blooms on old wood and should only be pruned to remove dead branches and old blooms.
Panicle hydrangeas (H. paniculata): panicle hydrangeas bloom on new wood, so they should be pruned in late winter or early spring by cutting back 1/3 of their total height. This will promote stronger stems, bigger buds, and more flowers.
Cascade hydrangeas (H. x): no need to prune cascade hydrangeas, as they bloom on old AND new wood! You’ll get the best performance if you avoid pruning.
Climbing hydrangeas (H. petiolaris): climbing hydrangeas bloom on old wood, so they flower best if you do not prune them.