when should you prune hydrangeas
You should prune hydrangeas at different times depending on the type: some right after flowering in summer, others in late winter or early spring before new growth starts.
Key rule: old wood vs new wood
Hydrangeas are mainly divided into two pruning-timing groups.
- Old wood bloomers : flower buds are formed the previous summer, so pruning too late (fallâspring) cuts off this yearâs blooms.
- New wood bloomers: flower buds form on the current seasonâs growth, so pruning is safest in late winter or early spring.
Think of âold woodâ as last yearâs branches carrying this yearâs flower buds; ânew woodâ is the fresh stems that appear in spring.
When to prune by hydrangea type
Bigleaf, oakleaf, mountain, and climbing (old wood)
These include bigleaf (Hydrangea macrophylla), oakleaf (H. quercifolia), mountain (H. serrata), and most climbing hydrangeas.
- Best time:
- Right after flowering finishes in late spring or summer.
- What to do:
- Remove spent flower heads and the oldest, weakest, or crossing stems.
- Lightly shape the shrub, but avoid hard cutting back.
- What to avoid:
- Do not prune heavily in fall, winter, or early spring, or youâll remove the buds for the coming season.
Example: A mophead hydrangea covered in blooms in June should be deadheaded and lightly thinned soon after the flowers fade, not in March.
Panicle and smooth hydrangeas (new wood)
Panicle (Hydrangea paniculata) and smooth (H. arborescens) hydrangeas bloom on new wood.
- Best time:
- Late winter to very early spring, before strong growth begins.
- What to do:
- For panicle types: shorten stems, keeping a sturdy framework; heavier pruning gives fewer but larger flower heads.
* For smooth types: cut back to about 12â18 inches from the ground for big blooms, or prune more lightly for more but smaller flowers.
- Flexibility:
- Light shaping just after flowering is usually fine and will not harm next yearâs buds.
Reblooming and mixed types
Some modern varieties rebloom on both old and new wood.
- Timing options:
- Light prune in early spring, or
- Light prune after the first flush of flowers has faded.
- Trade-off:
- Early pruning can delay the first blooms; mid-season pruning can slightly shorten the reblooming window.
Simple timing cheat sheet
| Hydrangea type | Wood type | When to prune | How hard to prune |
|---|---|---|---|
| Bigleaf (mophead, lacecap) | Old wood | [1][3]Right after flowering in summer | [3][1]Light shaping; remove dead/old stems | [1]
| Oakleaf | Old wood | [1]After flowering, minimal pruning | [1]Only dead, damaged, or too-large stems | [1]
| Mountain | Old wood | [1]After flowering | [1]Light shaping, remove dead wood | [1]
| Climbing | Old wood | [7][3]Late summer after flowering | [7]Thin or shorten shoots as needed | [7]
| Panicle | New wood | [3][1]Late winter to early spring | [3][1]Moderateâhard, leaving a strong framework | [1]
| Smooth | New wood | [3][1]Late winter to very early spring | [3][1]Cut back to 12â18 in. for big blooms | [3][1]
| Reblooming hybrids | Old & new wood | [8][5]Early spring or just after first flush | [5]Light, careful pruning, preserve old stems | [5]
Quick âwhat should I do now?â guide
- If it is late winter or early spring:
- Safely prune panicle and smooth hydrangeas.
- For bigleaf/oakleaf/mountain/climbing, stick to removing only clearly dead or damaged wood to avoid losing blooms.
- If it is mid-to-late summer:
- Deadhead and lightly prune old-wood types after they finish flowering.
- You can also deadhead new-wood types without affecting next yearâs flowers.
A practical example: if your hydrangea is a big, floppy smooth hydrangea and itâs late winter, you can cut it back hard to a foot or so to get fewer but very large flower heads in summer.
Information gathered from public forums or data available on the internet and portrayed here.
