Pruning hydrangeas can seem intimidating, especially if you've heard stories of overzealous pruning leading to a year without blooms. The key to successful pruning lies in understanding the specific needs of each hydrangea type, as their pruning requirements differ based on whether they bloom on new or old wood. Start by identifying the type of hydrangea in your garden, then follow this guide to determine the best time and method for pruning.
Mophead Hydrangeas (Hydrangea macrophylla)
How to Identify: These are the traditional hydrangeas with heads full of flowers and glossy leaves.
Common Varieties: ‘Endless Summer’, ‘Nantucket Blue’, ‘Big Daddy’
Blooms on: Traditionally on old wood, but newer, reblooming varieties now bloom on BOTH new and old wood.
When to Prune: Late summer, after flowering.
How to Prune:
Very little pruning is needed, just remove dead or damaged wood in spring when you see which stems start to leaf back out.
After the blooms fade in late summer, cut back the flowering stems to a pair of healthy buds if you’d like to encourage faster reblooming. OR wait until early spring to leave the dry blooms for some winter interest.
Avoid heavy pruning as Mopheads bloom on old wood, and removing too much can reduce next year's blooms.
Lacecap Hydrangeas (Hydrangea macrophylla)
How to Identify: Small blooms in center with larger blooms radiating around.
Blooms on: Old wood. There are some reblooming Lacecaps as well, which bloom on new AND old wood.
Common Varieties: ‘Endless Summer Twist & Shout’, the ‘Tuff Stuff’ series (Hydrangea serrata), ‘Let’s Dance Can Do’ ‘Blue Wave’
When to Prune: Late summer, after flowering.
How to Prune (same as Mophead hydrangeas):
Very little pruning is needed, just remove dead or damaged wood in spring when you see which stems start to leaf back out.
After the blooms fade in late summer, cut back the flowering stems to a pair of healthy buds if you’d like to encourage faster reblooming. OR wait until early spring to leave the dry blooms for some winter interest.
Avoid heavy pruning as Lacecaps bloom on old wood, and removing too much can reduce next year's blooms.
Arborescence Hydrangeas aka Annabelle type (Hydrangea arborescens)
How to Identify: Huge flower heads, big balls of smaller blooms and heart-shaped leaves.
Common Varieties: ‘Annabelle’, ‘Incrediball’, ‘Invincibelle Spirit’
Blooms on: New wood.
When to Prune: Late winter or early spring.
How to Prune:
Cut the stems back to about 12-15 inches above the ground in late winter or early spring before new growth starts.
Will re-grow to full height with new wood in a season.
This encourages strong new growth and larger blooms.
Panicle Hydrangeas (Hydrangea paniculata)
How to Identify: Cone-shaped blooms with typical hydrangea leaves.
Common Varieties: ‘Limelight’, ‘Grandiflora’ (Pee Gee), ‘Quick Fire’
Blooms on: New wood.
When to Prune: Late winter or early spring.
How to Prune:
Prune in late winter or early spring before new growth begins.
Pruning these aggressive, fast growing hydrangeas will really help to shape the plant and prevent the problem of the large blooms bending the long stems down toward the ground once they are fully open. This is especially true for paniculata types in deeper shade.
Cut back the previous year's growth to about one-third of its length to maintain shape and encourage vigorous blooming.
Oakleaf Hydrangeas (Hydrangea quercifolia)
How to Identify: Stacked cone-shaped blooms with leaves that are similar to an oak and turn red in the fall.
Common Varieties: ‘Snow Queen’, ‘Alice’, ‘Ruby Slippers’
Blooms on: Old wood.
When to Prune: After flowering in mid-late summer.
How to Prune:
Go light with pruning (if any at all) so you don’t cut off next year’s flower buds! Just prune back as needed to keep your shrub from becoming unruly.
Prune immediately after flowering is finished, cutting back the flowering stems to a pair of healthy buds.
General Pruning Tips
Tools: Use sharp, clean pruning shears to make clean cuts and prevent disease.
Sanitation: Clean your tools with a disinfectant before and after pruning to avoid spreading diseases.
Deadheading: You can remove spent blooms regularly to promote continued blooming and maintain a tidy appearance, but it isn’t necessary. Leaving dried blooms on your shrub can provide winter interest.
