Hydrangeas Wilt: UK Gardens Face Heatwave Crisis

Hydrangeas, once a resilient staple in British gardens, are now facing significant challenges due to hotter summers. Data from the Royal Horticultural Society (RHS) reveals a more than threefold increase in inquiries about drought and heat damage affecting these popular shrubs since 2023. This surge has placed hydrangeas at the top of the list for plants reporting hot weather problems, rising from seventh to first place between 2023 and 2025, and continuing this trend in 2026.

In response to these changing conditions, the RHS is considering a significant horticultural shift. The charity is evaluating the relocation of its extensive hydrangea collection from its Wisley garden in Surrey to its northern gardens located in Great Manchester and North Yorkshire. These northern locations are anticipated to offer a more suitable climate, with less intense heat and dryness, compared to the south of England.

Experts at the RHS note that while certain hydrangea varieties, particularly Hydrangea macrophylla types, suffer in sunnier and sandy soils, others like Hydrangea paniculata can perform well in shadier or moister conditions. The charity's trial at its Manchester garden (2021-2025) exposed hydrangeas to challenging weather, including drought and record heat in 2022, impacting their bloom quality. As a result, gardeners are advised to protect hydrangeas by moving potted plants to dappled shade, watering deeply, mulching, and potentially relocating those in full sun to shadier spots during the autumn.