When is it too late to cut back hydrangeas? Experts reveal the final cut-off point

It’s easy to become overwhelmed with the endless amount of gardening required in spring. From sowing seeds to mowing your lawn for the first time, cutting back hydrangeas may slip your mind. But if you’ve forgotten this essential job, you might be wondering: When is it too late to cut back hydrangeas?

Knowing when to prune hydrangeas is as important as knowing when to plant hydrangeas and how to take hydrangea cuttings. You could say that pruning is even more important, as annual pruning is key to bigger and bolder blooms year on year. And what’s a hydrangea without its famous showy flowers?

However, cutting back hydrangeas too late could be disastrous for these romantic blooms and actually stop them from flowering. So, we’ve consulted with the experts to determine the cut-off point.

When is it too late to cut back hydrangeas?

Like many other plants in your garden, cutting back and pruning hydrangeas will keep this plant happy and healthy throughout the year. Timing is everything when cutting back hydrangeas, though.

Although hydrangeas are hardy and do require deadheading, they’re still susceptible to cold temperatures and frost. That’s why it’s always a good idea to keep the spent flowerheads on your mophead and lace cap hydrangeas throughout the winter months. In fact, these flowerheads will offer a layer of protection to the plants.

So, when should you aim to prune them? Steve Chilton, garden expert at LeisureBench, explains, ‘The best pruning time for the majority of hydrangeas is March-April, or just early spring. I wouldn't recommend pruning them after this time as they need to be ready for flowering in summer.’

In fact, pruning them too late could stunt the growth of new flowers completely, and could see your cottage garden ideas fall short. That’s why you should add cutting back hydrangeas to your list of jobs to do in the garden in April.

‘Some varieties need to be pruned after flowering, but it all really depends on the exact type of hydrangea you're growing,’ adds Steve. ‘Pruning in summer is never recommended and neither is pruning in winter. When pruning, always cut just under the flower head and above any new buds in order to encourage growth. Learning how to sharpen secateurs properly can make pruning a lot easier.

And while May would be way too late to prune your mophead and lace cap hydrangeas, the rules are a little different when it comes to climbing hydrangeas, which have different pruning requirements. If you have climbing hydrangeas, you should prune them immediately after flowering in late summer (i.e., August or September).

Pruning them any later than that will once again affect their growth. That’s because climbing hydrangeas produce new flowers on last year’s shoots. If you don’t give them enough time to produce new flowering wood, you can kiss your flowers goodbye next flowering season.

This is also something you really need to consider if you’re looking to move your hydrangea. It’s easiest to do this when the plant has been pruned, but you can’t move a hydrangea unless it’s dormant. So, you need to time your hydrangea jobs perfectly.

Steve Chilton

Steve is a passionate and knowledgeable garden expert with several years of experience within the field and has developed strong expertise for all things nature and plants. Steve is a keen educator and loves to share this knowledge with others. He strives to simplify complex garden practices and encourage eco-friendly gardening.

FAQs

Can I cut my hydrangeas back now?

You should always aim to cut back your hydrangeas in early spring, around March or April time. This will allow the spent flowerheads to protect the plant throughout the colder, winter months and result in bigger and bolder blooms later in the year.

When should I cut the flowers off my hydrangea UK?

If you have mophead and lacecap hydrangeas, you should leave the flowers on your hydrangea throughout the winter months, even if they no longer look as pretty as they once did. This is essential to the health and well-being of the plant and will help it get through the colder months.

If you have climbing hydrangeas, however, it’s best to cut the flowers off your hydrangea after flowering in late summer.

What month should I stop deadheading my hydrangea?

This really does depend on the type of hydrangea you have. If you have lacecaps or mopheads, you should aim to deadhead and prune them in early spring. If you leave it any later than that (for example, in the summer), you may affect the growth of the new flowers.

So, don't wait too long to cut back your hydrangeas.