The resilient garden

Resilience is the new watchword in garden design. In Britain, the once gentle climatic conditions that were perfect for creating the green and fecund gardens so admired around the world are giving way to more extreme patterns. Warmer, wetter winters, periods of drought and increased summer temperatures – 40.3C was recorded in Lincolnshire in 2022 – are now common. Even in continental Europe, which is used to more dramatic weather, the trend is similarly pronounced: summer temperatures now regularly reach 42C in southern France and Italy, often for prolonged periods. Even a Mediterranean garden would struggle to deal with these conditions.

Garden designers are increasingly studying and cherry-picking planting and landscape techniques from across the globe that can be applied to different environments. Whether it’s hardy rose varieties from Kazakhstan, resilient trees from Asia, succulent sedum from North America or ingenious underground water-capture systems, advanced knowledge and inventive solutions are more in demand than ever. If you are hiring a garden designer, be sure to ask about theirexperience with these approaches.

In the UK, gardeners are finding that rising average temperatures increase evaporation, which dries soils faster, while rainfall is arriving in fewer but more intense bursts, rather than providing steady replenishment – a shift that climate projections indicate will continue, especially in southern and eastern counties. To counter this recurring challenge, resilience is all-important in soil, plant choice and water management, reducing stress for the plants – and garden owners too.

This doesn’t mean we need to rip out herbaceous borders and start again, but it’s well worth taking inspiration from gardens designed for drought, including Beth Chatto’s gravel garden near Colchester in Essex, or the newly created Delos garden at Sissinghurst Castle in Kent, where Mediterranean oaks are underplanted with dry and shade-tolerant species. The walled garden at Knepp Castle in West Sussex is particularly clever. Instead of the usual herbaceous border stars, it includes silver and leathery-leafed plants that have evolved to deal with heat, while eryngiums, grasses, red hot pokers, euphorbias and sedums – many of which originate in the Mediterranean, South America and Asia – thrive in the harsh conditions.

Nicola Pusterla, a designer with Tom Stuart-Smith’s studio in Hertfordshire who has worked extensively in the Mediterranean, warns that although these schemes may not need much watering once the plants are established, they necessitate considerable thought when planting and tending. “If anything, these planting schemes require more attention and skill, because you’re going to be dealing with grasses, herbaceous plants, shrubby plants, subshrubs and so on,” he says. “You need to treat every plant individually – you have to deal with the life expectancy of the plants, and how they regenerate.”

Pusterla cites lavenders such as L dentata: “They grow fast and might swallow their neighbours, then after two years they are gone, especially if you overwater them. But you can clip them and have fresh growth from the base, so they never age too much.”

For those with established gardens, change doesn’t have to be radical. Sometimes it is simply a matter of tweaking. Alexander Hoyle, a designer based in London and Wiltshire who has worked in challenging climates as far afield as Pakistan, Morocco and Azerbaijan, is optimistic about how we can adapt as we go, replacing vulnerable plants with varieties already in our canon that will achieve the same effect but are more resilient to extremes. “You don’t have to reinvent the wheel,” he says. “You can still have the same floral calendar.”

For height, Hoyle suggests, “you might put in loads of hollyhocks instead of your delphiniums, and have fewer lupins.” He also recommends beefing up on bearded irises (Iris germanica), the rhizomes of which positively enjoy baking in the sun – the Benton End varieties, which are becoming increasingly available, have especially lovely hues. “Thalictrum seems to grow quite well if it doesn’t have a lot of water, and Libertia grandiflora is a fantastic plant – it will grow anywhere,” Hoyle says. As for valerian (Centranthus ruber): “It is my favourite plant. I love the white one.”

For leading designer Marcus Barnet, responding to the realities of climate change means creating landscapes that are adaptable andfuture-proof. “Wherever possible, we prioritise native and site-appropriate species that are naturally suited to local conditions,” he explains. “We focus on drought-tolerant planting strategies that reduce irrigation demand while still delivering seasonal richness and colour.” He also points to the increasing popularity of wildflower meadows that strengthen ecological networks – and look dreamily beautiful.

Plant breeders, too, are responding to the new climate: research programmes are selecting for deeper roots and efficient water use, while participatory trials are accelerating the arrival of cultivars that perform in variable conditions. For example, although roses are generally drought-tolerant, there are exciting developments in the breeding of Rosa persica varieties by specialists such as Harkness Roses and Warners Roses. Natives of Iran, Kazakhstan and Afghanistan, these roses are used to searing conditions and have a semi-wild appearance, with blushed centres.

Planting trees now entails trying to look even further into the future and second-guessing the role the tree will play in the garden – from the shade it will provide to its ability to slow rainfall and deal with a lack of water. For a directory of more than 500 types chosen for their resilience, consult The Essential Tree Selection Guide: For Climate Resilience, Carbon Storage, Species Diversity and Other Ecosystem Benefits by Henrik Sjöman and Arit Anderson (Kew Gardens, £50).

Improving soil’s organic matter increases water‐holding capacity, and mulching can cut surface evaporation dramatically (and ward off weeds, which compete for water). Both are simple measures that help plants to ride out longer dry intervals. Harvesting rainwater from roofs into water butts and even subterranean tanks provides a free supply, although Pusterla prefers to create lakes that can be pumped, if space allows. “It is also valuable for biodiversity,” he says. “You let the water go back into the water table, then just pump the right amount.”

As for the lawn, instead of mowing it to a crew cut, then watering wildly to keep it emerald during a dry period, perhaps let it grow longer – come the autumn rains, it will green up again. What we expect of our gardens must change along with the climate but, carried out in the right spirit, change can be refreshing.

This story also appears in the new Portfolio magazine. Request your complimentary copy here.