With their huge pompom blooms and long flowering seasons, they’re one of the great showstoppers of the British garden – but, if you’re wondering how to revive woody hydrangeas like a pro, you’re not alone.
Hydrangeas are one of the easiest and most popular ways to brighten garden borders from early summer well into autumn. But after a few years, many gardeners notice the same frustrating problem: their once-lush hydrangea has become woody, leggy and stubbornly reluctant to flower (boo, hiss!).
It’s a common issue, particularly with older hydrangeas that haven’t been pruned for a while. Over time, hydrangeas can develop thick, woody stems that produce fewer fresh shoots, which in turn means fewer of those spectacularly showy flowers, even if you’ve chosen the right time to deadhead them. The good news, however, is that a tired-looking hydrangea is rarely beyond saving.
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How to revive woody hydrangeas
With the right pruning technique and a little patience, you can absolutely revive woody hydrangeas. In fact, many gardeners are surprised by just how dramatically hydrangeas can bounce back once they’re given the chance to produce new growth.
Before you even think about cutting anything back, though, it’s important to know what type of hydrangea you’re dealing with. Different varieties flower on different types of wood, and pruning at the wrong time can accidentally remove the very buds that would have produced this year’s flowers.
As Morris Hankinson, director of Hopes Grove Nurseries, explains, understanding your hydrangea variety is the key to bringing an old plant back to life.
‘There are several common woody hydrangea types gardeners grow,’ he says.
‘Hydrangea macrophylla – often known as mophead or lacecap hydrangeas – flower on old wood, while Hydrangea paniculata and Hydrangea arborescens flower on new wood.’
This distinction matters because pruning the wrong stems at the wrong time can remove the buds that would have produced this year’s flowers.
Hydrangea macrophylla forms its flower buds the previous year, meaning aggressive pruning in spring can eliminate blooms. Paniculata and arborescens varieties, however, produce flowers on new growth, making them far more forgiving when it comes to pruning.
Once you’ve identified what you’re working with, you can move on to the following steps…
1. Check for winter damage first
Before doing any major pruning, it’s worth checking whether winter has damaged parts of the plant.
‘Wait until late spring when new growth appears,’ advises Hankinson. ‘Try the scratch test: lightly scrape the bark with your fingernail. If it is green underneath, the stem is alive. If it is brown and dry, that section has died.’
He also recommends looking closely for other signs of life. ‘Check the plant for hollow stems, split wood and signs of buds,’ he says. ‘If there aren’t any swelling buds, this could potentially be a sign the hydrangea hasn’t made it through winter.’
Removing clearly dead stems first helps you see what healthy growth remains and prevents unnecessary pruning.
2. Prune
If you’re growing hydrangea macrophylla, restraint is essential when trying to revive a woody plant.
‘Only remove dead, damaged and diseased stems, cutting back to green wood using the scratch test,’ says Hankinson. ‘You can also remove the tips if they’ve been damaged over winter.’
Because this variety flowers on old wood, heavy pruning can accidentally remove the buds that would produce this year’s blooms.
‘The key is patience,’ he explains. ‘Even if the top growth has died, new shoots might still appear. Flowers will grow on old wood, so too much pruning will mean fewer, or no, flowers this year.’
If your plant is a hydrangea paniculata or hydrangea arborescens, gardeners can be much more confident with their pruning.
‘These varieties are able to take a harder prune in spring,’ says Hankinson. ‘Stems can be reduced to around 25cm to 60cm from the base, and smooth hydrangeas can even be pruned back to ground level.’
Because these hydrangeas flower on new growth, cutting them back encourages fresh shoots that will produce blooms later in the same season.
‘Always use sharp secateurs and make a clean cut just above a bud,’ he adds.
3. Help your hydrangea recover after pruning
Once pruning is complete, a little aftercare can help the plant recover and produce strong new growth.
‘After pruning, lightly feed with a balanced slow-release fertiliser, water deeply and mulch around the base,’ Morris recommends. ‘Just make sure the mulch isn’t too close to the stems.’
It makes a lot of sense; after all, mulching helps protect the roots, improve soil moisture and regulate temperature around the plant. We’re big fans, basically.
FAQs
How to bring hydrangeas back to life?
If you want to bring your hydrangea back to life (or, y’know, you’re sick of it looking like a bunch of grey, brittle sticks come early spring), then Christopher O’Donoghue, director of Gardens Revived urges patience.
‘Before you play Dr Frankenstein, scratch a stem to see if it’s green underneath,’ he advises. ‘If it’s green, leave it alone. If it’s brown and snappy all the way through, that specific stem is dead.’
Whatever you do, Christopher says the trick is not to panic-prune in March. ‘Many varieties (like Bigleaf) bloom on “old wood,” and those dead-looking sticks are actually holding this year’s flowers,’ he points out.
‘If the leaves are yellow with green veins (chlorosis), the soil pH might be off or it needs iron. A dose of an acidic fertiliser can often wake them up.’
How far can you prune back woody hydrangeas?
If you want to prune back woody hydrangeas without accidentally killing off next year’s flowers, then you need to spend some time swotting up on hydrangea types, says hen Christopher O’Donoghue, director of Gardens Revived.
‘Hydrangeas annoyingly defy that one-size-fits-all approach to gardening,’ he says. ‘Some grow on new wood and can be cut right back; others grow on old wood and need to be treated far more carefully.’
With time, care and the right pruning approach for your specific variety, even a very woody hydrangea can be brought back to life. And, if you keep on top of it all, you’ll find yourself rewarded with healthier growth and better blooms for many more seasons to come, too.
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