DROUGHT-TOLERANT PLANTS: EVERYTHING YOU NEED TO KNOW

With summers predicted to get hotter, and water becoming a precious resource, everyone is talking about drought-tolerant plants. But are they the answer in the UK and what should we know about planting and caring for them? We ask plant experts and landscape designers for their advice

- VERONICA PEERLESS

What makes a plant drought tolerant?

Drought-tolerant plants often hail from Mediterranean climate zones around the world - around the Mediterranean sea, the western cape of South Africa, coastal California, central Chile and southern and southwestern Australia. They have evolved to thrive in habitats that have a very long, extremely hot and dry season - as much as six months with no rain - and poor soil.

Leaves may be small or thin, grey or glaucous, hairy, succulent or fleshy. Many have very deep or wide root systems that seek out water, or underground storage organs (bulbs). Drought-tolerant plants are often low growing and form mounds - less likely to be dried by wind on a hot day. In their native habitats, they may go dormant or lose their leaves in summer.

Are Mediterranean plants suitable for the UK?

Garden designer James Basson, based in the South of France, points out: "The UK may increasingly have extremes of heat and wet through climate change, but its gardens have a depth of topsoil from our past temperate era, which makes conditions very different to the arid Mediterranean." The plants he uses tolerate five to six months' heat in Provence without rain in summer; droughts in the UK are more likely to last a few weeks.

"There's a well-established climatic divide between the east and west of the British Isles," says garden designer Matthew Wilson, who designed the famous Dry Garden at RHS Garden Hyde Hall. "This is more important than north/south in many ways. I've planted the same drought-tolerant plants that I have in my own garden in the east Midlands in gardens as far south as the Solent and as far north as Hexham in Northumberland, including Eryngium, Salvia, Stipa, Pennisetum and Artemisia. But I would probably think twice before trying them in a garden in Wales, Cornwall or the west coast of Scotland.