Are Some of Our Favourite Garden Plants Beginning to Struggle?

The future of planting design isn't about finding a handful of "climate-proof" plants. It's about creating resilient plant communities that work with nature, support biodiversity and continue to thrive as our climate changes.

Think of the now familiar combination of Salvia 'Caradonna' and the steel-blue flowers of Eryngium. Once considered something of a specialist planting palette, these drought-tolerant perennials are becoming increasingly common in gardens and public landscapes as designers respond to hotter, drier summers. Photo credit & thanks to Jason Ingram.

Following my recent post, Richard Cocker asked a brilliant question: "Have you seen a trend of plants that are no longer thriving in the UK?" The honest answer is yes and no. It's not that familiar garden plants have suddenly become impossible to grow. Rather, a succession of hotter, drier summers is revealing which species are naturally more resilient and which increasingly depend on irrigation, cooler conditions or moisture-retentive soils.

What's particularly interesting is that this isn't a new conversation. Leading planting designers Piet Oudolf, Nigel Dunnett, James Hitchmough and Thomas Rainer have all been exploring how planting design should respond to a changing climate for many years.

Drawing on the work of Professor Nigel Dunnett, together with guidance from the Royal Horticultural Society (RHS), the following plants can struggle during prolonged periods of heat and drought, particularly in exposed or free-draining gardens:

Plants showing signs of stress:

• Hydrangea
• Hosta
• Astilbe
• Ligularia
• Rodgersia
• Primula
• Delphinium
• Lupins
  

That doesn't mean these plants no longer have a place in our gardens. It simply means they increasingly benefit from thoughtful positioning, improved soil moisture, shade or supplementary watering. Across the work of Nigel Dunnett, James Hitchmough, Thomas Rainer and the RHS, a different group of plants appears time and again for their ability to cope with challenging conditions:

Plants proving more resilient:

• Salvia
• Achillea
• Eryngium
• Nepeta
• Verbena bonariensis
• Perovskia (Russian Sage)
• Stipa
• Helictotrichon
• Dianthus

As featured: Carol Klein champions climate-resilient planting at RHS Hampton in 2023 with plants that thrive in hot, dry, and arid conditions. Her approach focuses on drought-tolerant perennials and structural plants that maintain a lush, abundant, and wildlife-friendly aesthetic without relying heavily on intensive watering.

As Professor Nigel Dunnett wrote of Olivier Filippi’s work on dry gardens:

“Learning from nature can give us the best of all worlds: beautiful and sustainable gardens with a unique sense of place.”

That feels like the opportunity before us. Some familiar plants may struggle, and our gardens may need to change, but that does not mean accepting something less beautiful. By responding intelligently to soil, climate and place, we can create gardens that are more resilient, more diverse and every bit as inspiring.