When to prune climbing hydrangeas – because striking at the wrong time can spoil next year’s blooms!

Hydrangeas are beautiful plants, and if you’re lucky enough to own a climbing one, an annual trim will keep the shoots in check. Of course, to start with, you’ll need to know when to prune climbing hydrangeas.

Learning how to grow climbing hydrangeas is fairly straightforward, but when it comes to pruning, you’ll need to strike at the right time. Different species of hydrangea flower in different ways – some on old wood, some on new – and trimming them out of season can wipe out next year’s blooms.

Knowing when to prune hydrangeas in pots and garden borders is one thing, but what about the climbing kind? I checked in with a few plant experts to find out.

What you'll need

• A pair of secateurs, like the WOLF-Garten Bypass Secateurs from Amazon
• A garden trug to collect plant material, like the Heritage Garden Trug from B&Q

If you only remember one thing when it comes to figuring out when to prune climbing hydrangeas, it’s this: wait until after the plant has finished flowering.

‘Any pruning should be carried out as soon as possible after flowering,’ says Annelise Brilli, horticultural expert at Thompson & Morgan.

Climbing hydrangeas usually stop flowering towards the end of summer, so late summer is the best time to prune them. We’re a little past that now – so if you haven’t trimmed your plant already, it’s best to hold off until next year. In fact, pruning now runs the risk of cutting off next year's flowers-to-be.

You can plant hydrangeas now, though. Hydrangea petiolaris from Crocus is a reliable variety, producing lacy white flowerheads from May to July.

The best way to prune hydrangeas depends very much on the type you’re growing, but with climbing hydrangeas, less is more. That’s according to the team at Sissinghurst Castle Garden, too, where author and gardener Vita Sackville-West once planted a climbing hydrangea on the west-facing wall.

‘The team find very little pruning is required, other than the very occasional trim to reduce it back to the wall a little,’ says Sissinghurst Castle’s head gardener, Troy Scott Smith.

In fact, hard pruning can do the plant more harm than good.

‘The flowers form at the ends of last year’s cascading stems, and extensive cutting back of these reduces flowering buds,’ explains Annelise.

I find that a quality pair of secateurs can turn pruning into a really fun task. Spear & Jackson’s Razorsharp Advantage Bypass Secateurs from Amazon are just £9.95, and the best budget pair I’ve tried – but if you’re looking for a really luxurious pruning experience, Niwaki’s Sentei Secateurs, also available at Amazon, are a dream to work with.

So, while there are lots of things you can do with hydrangeas in the autumn, pruning isn't one of them if you've got a climbing variety.