Hydrangeas at Risk: RHS May Move Blooms North Due to Hotter 2026

Hydrangeas are facing a serious threat from hotter summers and heatwaves, prompting the Royal Horticultural Society (RHS) to consider relocating its collection to northern England. This beloved shrub, known for its lush blooms and color-changing flowers, is struggling in the south as drought and heat damage reports triple since 2023.

Why Hydrangeas Are Suffering in Southern Gardens

The RHS gardening advice service has seen a dramatic rise in inquiries about hydrangeas affected by drought and high temperatures. In 2023, hydrangeas ranked seventh among plants with heat-related problems; by 2025, they jumped to first place, and they remain the most frequently reported plant for hot weather issues in 2026. With over 600,000 members, the RHS can easily spot garden trends and worries through these queries.

Guy Barter, chief horticulturist at the RHS, explains: “Hot dry summers are not the best for hydrangeas, although it is mainly the Hydrangea macrophylla types (mophead and lacecaps) that suffer most, especially in sunnier sites and sandy soils such as we have at Wisley.” The charity is now considering moving its hydrangea collection from Wisley, Surrey, to its northern gardens in Greater Manchester and North Yorkshire, where conditions are expected to remain more favorable.

The Climate Shift and Its Impact on Gardening

Climate change is bringing hotter, drier summers to the UK, forcing gardeners to adapt. The RHS’s northern gardens have better soils and a superior climate for hydrangeas, making them a safer haven for these plants. As Barter notes, “In light shade, north facing slopes or where the soil is a bit moister, they remain a fantastic plant for summer flowers, especially the more resilient Hydrangea paniculata.”

This shift highlights a broader trend: gardeners must become more selective about where they plant hydrangeas and other heat-sensitive species. The RHS’s study at its Manchester garden in Bridgewater is already examining how hydrangeas fare in cooler, wetter conditions.

Comparison of Hydrangea Performance: South vs. North

Key Takeaways for Gardeners

• Choose resilient varieties like Hydrangea paniculata for sunnier, drier spots.
• Plant in light shade or north-facing slopes to reduce heat stress.
• Improve soil moisture by adding organic matter and mulching.
• Water deeply but infrequently to encourage deep root growth.
• Consider moving vulnerable plants to cooler microclimates in your garden.

How to Protect Your Hydrangeas in Hotter Summers

If you live in southern England or other heat-prone areas, you can still enjoy hydrangeas with proper care. Provide afternoon shade, use drip irrigation, and avoid planting in sandy soils without amendments. Regularly check for signs of heat damage, such as wilting leaves or brown edges, and act quickly.

For those in cooler regions, the RHS’s move north serves as a reminder to leverage local climate advantages. By selecting the right species and planting locations, you can keep hydrangeas thriving despite global warming.

FAQ