As September is fast approaching, a common question on every gardener’s mind is whether they should prune their hydrangeas in order to protect them from the cold weather.
However, it depends on the type of hydrangea flowers and if you own either old wood or new wood hydrangea.
Old wood hydrangea will not produce flowers until the next season, which means their flower bud will have already formed. If pruned, gardeners can risk destroying next year’s flowering so should only be done if necessary.
New wood hydrangeas form their flower buds in spring, which means they can be pruned. If your hydrangea bloomed before June you likely own old hydrangea, while if they are flowering now they are likely new wood hydrangea.
A gardening expert explained that it is likely best to leave hydrangea alone. Pollyanna Wilkinson is a multi-award-winning gardening designer who has explained that the best way to take care of hydrangea in the winter is to know what species of hydrangea you own, but most hydrangea plants should not be cut.
In a TikTok video, Pollyanna said: “I want to talk to you about hydrangea care now. Look, I know [they will] be going brown but they’re meant to. Do not cut them! Let them go brown and stay that way over winter. It is much more interesting than looking at bare earth.”
Most hydrangea should be pruned in spring with the exception of climbing hydrangea, which should be pruned in late summer after they have flowered.
Hydrangea paniculata and adolescents are types of hydrangea which are new wood and can be pruned, but Pollyanna has suggested they are best left until spring. She said: “Just leave them and we’ll cut them down to about 30cm in the spring.”
Hydrangea lacecap and mophead are old wood hydrangeas and Pollyanna suggested you do “very little with them.”
Pollyanna said: “Leave the flowers to go brown, just like you would the other ones, but with these, you might take out one or two stems come the spring but otherwise they don’t need much pruning.”
Hydrangeas that bloom from old wood need extra protection during the wintertime to make sure their flower buds survive, while new wood hydrangeas have higher frost resistance.
Morris Hankinson, the gardening director of Hopes Grove Nurseries, spoke to Express UK and explained that hydrangeas are quite “hardy” plants in the wintertime but agreed that hydrangeas are unlikely to need pruning.
Morris said: “Leaving the old flowers on the shrub over the winter can help to protect the young buds that will provide flowers for next year.”
He added: “The only danger from cold weather is with late frosts damaging the young developing shoots in the spring, avoiding frost pockets when planting is the best defence against this.”
Some gardeners chose to protect their hydrangea with a horticultural fleece in the wintertime. Morris said: “If your hydrangea is in full growth in the Spring and a frost is forecast – you could cover the plant overnight with some horticultural fleece to minimise the damage.”