The When and How of Pruning Hydrangeas
June 13th, 2025 | Categories
Hydrangeas are the showstoppers of so many gardens with their beautiful blooms in dreamy shades of blue, pink, white and purple brightening up any corner. But if you want your hydrangeas to keep flourishing year after year, well-timed pruning is key. When not pruned, hydrangeas can become overgrown, tangled, dense messes, almost completely unrecognisable and undesirable. So, pruning is crucial. The best time to prune most hydrangeas is in spring between March and April and the actual pruning process isn’t nearly as tricky as it seems. With a little confidence (and a few tips from this guide), you’ll soon be shaping up your hydrangeas like a pro.
When to Prune Hydrangeas
The timing of your pruning all depends on the type of hydrangea you have. The key is understanding whether your hydrangea blooms on old wood or new wood:
- Old wood = stems that grew last year. Flowers develop on these older stems.
- New wood = fresh stems that sprout this year. Flowers develop on brand-new growth.
Knowing which type you have will help you prune at exactly the right time without accidentally snipping off next year’s flowers!
Here’s a simple breakdown for the different types of hydrangeas:
- Mophead and Lacecap (Hydrangea macrophylla)
Flowers on old wood, prune lightly to tidy in early spring, then a bigger prune immediately after flowering (late summer). Be gentle because too much spring pruning removes flower buds.
- Oakleaf (Hydrangea quercifolia)
Flowers on old wood, prune in late summer after flowering. Minimal pruning keeps their elegant, natural shape.
- Panicle (Hydrangea paniculata)
Flowers on new wood, prune in late winter to early spring before new growth starts. Can be pruned hard to encourage bigger, more dramatic flowers.
- Smooth (Hydrangea arborescens)
Flowers on new wood, prune in late winter to early spring before new growth starts. Thrives on a hard prune producing strong growth and blooms.
- Climbing (Hydrangea petiolaris)
Flowers on old wood, prune after flowering in the late summer or early autumn. Just a light tidy though, don’t cut back heavily.
A Handy Rule of Thumb
If your hydrangea flowers early in the summer (June to early July), it’s likely blooming on old wood – prune just after flowering.
If it flowers later in the summer (July to August), it likely blooms on new wood – prune in late winter or early spring before growth starts.
Should you Deadhead Hydrangeas when Pruning?
Deadheading – simply snipping off the faded flowers – is a way to keep your hydrangeas looking tidy. But with hydrangeas, there’s a little extra to think about compared to other garden plants. You’ll often see hydrangeas left with their papery old blooms all through autumn and winter and there’s some good reasons for it:
- Frost protection: the old flower heads act like little natural umbrellas, shielding the delicate new buds below from harsh winter frosts.
- Winter interest: On frosty mornings, those faded blooms catch the light beautifully, giving your garden a magical, sculptural look.
- Less chance of damage: Pruning too early can accidentally encourage new growth, which could be nipped by a late cold snap.
In short, leaving the old flowers on until early spring (March or even April if it has been a cold winter) is often the best thing you can do for your hydrangea and it offers some interest too when there’s not much going on. Always cut at a slight angle, just above the bud pair, to encourage water runoff and healthy growth.
If you like, you can deadhead during the summer too after flowering. As soon as a bloom fades and starts looking tatty, just snip it off above the next set of leaves. Some varieties, like newer reblooming hydrangeas (such as Hydrangea macrophylla ‘Endless Summer’), can produce a second flush of flowers if you keep deadheading lightly through the season.
How to Prune Hydrangeas: Step-by-Step
Here’s exactly how to prune each type of hydrangea:
Pruning Mophead and Lacecap Hydrangeas (Old Wood Bloomers)
These classic hydrangeas don’t need heavy pruning. In fact, too much cutting can reduce next year’s blooms.
Here’s what to do:
- Wait until after flowering. Ideally, once the blooms have faded but before autumn really sets in.
- Snip off spent flower heads. Cut back just above a pair of healthy buds lower down the stem.
- Tidy up. Remove any dead, damaged, or crossing stems completely at the base.
- Every few years: Remove one or two of the oldest stems at ground level to encourage fresh, vigorous growth.
Tip: Always use clean, sharp secateurs to make neat cuts and avoid damaging the plant.
Pruning Panicle and Smooth Hydrangeas (New Wood Bloomers)
Because these types flower on new growth, you can be a little bolder with your pruning.
Here’s the method:
- Prune in late winter or very early spring before the plant wakes up.
- Cut back hard. Trim stems back to around one-third of their height (about 30–50cm from the ground).
- Shape the plant. Aim for an open, vase-like shape to let light and air circulate through the plant.
Tip: Don’t be scared – hard pruning often results in even bigger, more impressive blooms!
Pruning Oakleaf Hydrangeas (Old Wood Bloomers)
Oakleafs bloom on old wood, so treat them like mopheads – only very light pruning straight after flowering. Mostly, you’ll just want to remove spent flowers and tidy up any dead or weak stems.
Tip: Oakleaf hydrangeas naturally have a lovely, graceful form, so avoid heavy pruning unless absolutely necessary.
Pruning Climbing Hydrangeas (Old Wood Bloomers)
Climbing hydrangeas bloom on old wood and pruning is best done shortly after flowering. However, you don’t really want to prune them a lot if at all unless you want to control their size or spread, or to remove dead and damaged stems, or to shape it better. Just prune enough to keep it tidy and growing well.
Extra Tips for Pruning Hydrangeas Like a Pro
- Don’t rush in: If in doubt, wait. Hydrangeas often look dead after a tough winter, but given a little time, new buds can still appear along the stems.
- Mulch after pruning: Help your plant recover and grow strong by adding a layer of compost or well-rotted manure around the base after pruning.
- Avoid pruning in very cold weather; Fresh cuts are more vulnerable to frost damage. Wait until the worst of winter has passed.
- Late frosts: If you prune too early and get a surprise frost, tender new growth can be nipped. It’s often best to wait until March or even early April in colder parts of the UK. If you’ve already pruned and expect a frost, consider protecting with garden fleece.
Pruning Hydrangeas Without the Fear
Hydrangeas are wonderfully resilient plants, and a little thoughtful pruning will do wonders for their health and beauty. The key is to know your type, prune at the right time, and remember that it’s absolutely fine to take it step-by-step as you build your confidence. Happy pruning and here’s to many seasons of glorious hydrangea blooms ahead!
