As autumn arrives, gardeners are busy preparing their plants for winter, but experts warn that one common task could harm hydrangeas. Pruning in autumn or winter may ruin the plant's chances of a strong bloom next year, according to the Royal Horticultural Society (RHS).
Hydrangeas' faded flowerheads provide essential frost protection for tender buds and shoots during cold months. The RHS advises leaving dead blooms on mophead hydrangeas over winter, removing them only in early spring by cutting back to the first strong, healthy pair of buds below the faded bloom.
For lacecap hydrangeas, which are more cold-resistant, pruning can be done in autumn. Trim back to the second pair of leaves below the flowerhead to prevent seed growth and conserve energy. In early spring, once frost risk has passed, a quick prune before new growth starts will encourage a fantastic flowering season.
If your hydrangea is overgrown or poorly shaped, drastic renovation is possible by cutting all stems at the base, but this will sacrifice flowers for that summer. New stems will bloom the following year.
September is also an ideal time to adjust soil pH for hydrangeas, as they prefer slightly acidic conditions. Adding special fertiliser now gives time to create optimal conditions by spring.
