When should you prune hydrangeas?
Short answer: It depends on the type. Bigleaf (mophead, lacecap), mountain, and oakleaf hydrangeas bloom on old wood, so prune just after flowering. Panicle and smooth hydrangeas such as 'Annabelle' bloom on new wood, so prune in late winter or early spring. Reblooming bigleaf types need only light pruning in early spring or after the first flowers fade.
Why does pruning time depend on the type?
Hydrangeas fall into two groups based on when they make flower buds.
- Old-wood bloomers form next year’s flower buds in late summer and fall. Pruning them in fall, winter, or spring cuts off those buds.
- New-wood bloomers form flower buds on the current season’s growth. Pruning them in late winter does not remove any buds.
University of Maryland Extension groups the species this way. Penn State Extension notes that pruning a bigleaf hydrangea in fall has the same effect as deer browsing it: fewer or no flowers next summer.
When to prune each hydrangea type
| Type | Botanical name | Blooms on | When to prune | How far back (if needed) |
|---|---|---|---|---|
| Bigleaf (mophead, lacecap) | Hydrangea macrophylla | Old wood | Just after flowering | To about 12 in. off the ground |
| Mountain | H. serrata | Old wood | Just after flowering | To about 12 in. |
| Oakleaf | H. quercifolia | Old wood | Just after flowering | About 12 in., or leave taller |
| Climbing | H. anomala subsp. petiolaris | Old wood | Just after flowering, if needed | Minimal |
| Smooth (‘Annabelle’) | H. arborescens | New wood | Late winter or early spring | About 12 in., or to the ground |
| Panicle (“peegee”) | H. paniculata | New wood | Late winter or early spring | About 12 in., or leave taller |
| Reblooming bigleaf or mountain | H. macrophylla (and mountain) | Old and new wood | Early spring, or after the first flush fades | As little as possible |
Sources: University of Maryland Extension for groups, timing, and heights. Penn State Extension notes smooth and panicle types can be cut “to the ground in late winter or very early spring” and still bloom well.
Neither source gives calendar months. “Late winter” arrives at different times in different climates. Our USDA hardiness zones guide can help you place your climate.
How do I tell which hydrangea I have?
Use the flowers and leaves together.
- Blue or purple flowers: Only bigleaf and mountain hydrangeas make blue or purple blooms, per University of Maryland Extension. Their color shifts between pink and blue with soil chemistry. White bigleaf types stay white.
- Round “mophead” or flat “lacecap” flowers: Likely bigleaf. Mountain hydrangeas have lacecap flowers that look nearly identical.
- Leaves shaped like oak leaves: Oakleaf hydrangea.
- Large white round flowers on a low shrub: Often smooth hydrangea, such as ‘Annabelle’. Some newer smooth types, like Invincibelle Spirit, are pink.
- Last of the group to bloom: Often a panicle hydrangea, per University of Maryland Extension. Old varieties are called “peegee.” It may be grown as a shrub or trained as a small tree.
- A vine clinging to a wall or tree: Climbing hydrangea.
If you still are not sure, check the plant tag or nursery receipt. When in doubt, skip pruning for a year and watch where the flowers form.
What about reblooming hydrangeas like Endless Summer?
Reblooming (remontant) bigleaf and mountain hydrangeas flower on both old and new wood. Penn State Extension lists reblooming bigleaf cultivars such as Endless Summer, Twist-n-Shout, BloomStruck, Summer Crush, and Blushing Bride as examples.
University of Maryland Extension advises removing as little wood as possible. Prune in early spring or after the first flush of flowers fades. Pruning early delays the start of blooming. Pruning mid-season may shorten the reblooming period.
Can I deadhead hydrangeas anytime?
Yes. Deadheading removes only the spent flowers at the branch tips. University of Maryland Extension says it can be done any time after flowers fade. It is not needed for plant health. It may help repeat-flowering types rebloom faster.
Why didn’t my hydrangea bloom?
For old-wood types, common causes are:
- Pruning in fall, winter, or spring, which removes the buds.
- Deer browsing the stems.
- A severe winter that kills flower buds or the whole top of the plant. Penn State Extension says this happens with bigleaf hydrangea, which is hardy in zones 6 to 9. Oakleaf (zones 5 to 9) is less prone to this damage.
New-wood types rarely lose blooms to pruning timing.
Quick answers
Should I cut back hydrangeas in the fall? Not bigleaf, mountain, or oakleaf types. Fall pruning removes next year’s flower buds. Smooth and panicle types are better pruned in late winter or early spring.
When do you cut back Annabelle hydrangeas? In late winter or early spring. Annabelle is a smooth hydrangea that blooms on new wood. It can be cut to about 12 inches or even to the ground.
When do you prune peegee or other panicle hydrangeas? Panicle hydrangeas bloom on new wood, so prune them in late winter or early spring. Large varieties can be left taller than 12 inches.
When do you prune mophead hydrangeas? Right after they finish flowering. Mopheads are bigleaf hydrangeas that bloom on old wood.
Do Endless Summer hydrangeas need pruning? Only lightly. Remove as little wood as possible, in early spring or after the first flowers fade.