This November hydrangea mistake could cost you next year's flowers – it's the surest way to ruin a hard-earned display

A fair amount of pruning can be carried out in autumn, but not every plant will benefit from a trim this month. Can you prune hydrangeas in November, though?

Well, according to experts, the answer is a resounding no. With so many different species and cultivars to choose from, I assumed we’d be able to prune some types of hydrangeas at this time of the year – but as it turns out, it’ll do your plants far more harm than good. In fact, knowing exactly when to prune hydrangeas is key to maintaining your plant's health.

So, if you’ve been wondering if you can prune hydrangeas in November, here’s what you need to know.

When it comes to pruning hydrangeas in November, there are two key drawbacks – and the first can directly impact next year’s flowers.

A lot of hydrangeas bloom on the previous year’s growth, so if you prune them this late in the year, you could unwittingly be removing next year’s buds. Pruning at the wrong time is actually one of the most common causes of hydrangeas not flowering.

‘If you have mophead or lacecap hydrangeas, these flower on the previous year's growth and should not be pruned until spring,’ confirms Richard Barker, horticultural expert and commercial director at LBS Horticulture.

That doesn’t mean hydrangeas that flower on new growth are in the clear, though.

‘Hydrangeas that produce flowers on new growth can be pruned when they are dormant, but the best time for this is in late winter or early spring,’ says Richard. ‘Although the plants will be dormant in autumn, you still run the risk of pruning cuts becoming more damaged by the cold and frost.’

Speaking of frost – just as you shouldn’t mow your lawn during freezing weather (that’s why knowing when to stop cutting grass for winter is so important), you shouldn’t prune hydrangeas ahead of the temperature drop we’re likely to see this November.

‘This is because their stems can hold moisture inside of them that can freeze over winter, and pruning can also expose the buds to winter weather,’ Richard explains.

Besides mulching hydrangeas, the flower heads of some species can even aid in frost protection.

‘Mophead and lacecap types retain old flowerheads through winter, shielding the buds that will bloom next year,’ says Annelise Brilli, horticultural expert at Thompson & Morgan.

Of course, autumn is one of the best times to plant hydrangeas – so if you're hoping to add a new shrub to your garden, now's the time to do it. Personally, I love Hydrangea arborescens 'Annabelle', which you can buy at Crocus from £9.99.

So, that's that: it's best not to prune hydrangeas this month. It'll save you a November garden job, at least!