A succulent solution to a fiery problem

When a fast-moving wildfire forced Suzy and Rob Schaefer to grab their most treasured possessions, jump in a car and flee their home in the San Diego dormitory town of Rancho Santa Fe, they feared they would come back to a burnt-out wreck.

Instead, the couple returned to find their property in one piece: flames had roared down the eucalyptus and palm-filled canyon above, lapped at the edges of their garden, scorched a few plants – and suddenly petered out within six feet of the building. Luck was certainly on their side. But so too was nature: the aloes, agaves and other "succulent" plants in their garden had acted as a fire retardant, stopping the blaze in its tracks. As the delighted email they sent friends and family that night explained, "succulents saved our home!"

They weren't the only ones. This week, a year after their escape, the Schaefers were reminded of their good fortune as the annual Santa Ana winds brought southern California's wildfire season to the fringes of Los Angeles, destroying 50 houses, killing a man, and forcing thousands from their homes.

The fire – which blackened 15,000 acres of hillside above the San Fernando Valley and filled much of the city with smoke – provided a graphic illustration of the dangers that are prompting unprecedented numbers of home owners, such as the Schaefers, to fill their gardens with "fire-proof" plants. After a long, hot summer that has seen millions of acres along America's tinder-dry Pacific coast go up in smoke, horticulturalists are reporting a surge in demand for succulents, which get their name from the way they store up water in their stems to survive drought.

"I've had a lot of calls from people who heard about my story and want advice," Mrs Schaefer said. "Local nurseries have suddenly started stocking huge amount of succulent varieties. People are so much more aware of what can happen in a fire, and what these plants can do to help. And also of how pretty they are."

The California Department of Forestry and Fire Protection advised home owners to plant succulents and cacti, and avoid large trees and other mature vegetation, which are prone to go up in smoke upon contact with sparks. While there is no such thing as a completely fire-proof plant, they say, slow-burning plants can create a "defensible zone" around properties.

"In the intense heat of a wildfire, there's nothing that's going to protect your house in all circumstances, but I'm getting more and more people asking for help in creating gardens that might make a difference," says Debra Lee Baldwin, author of the book Designing with Succulents. "You can line succulents up in a row like soldiers to create a wall against a fire, but the skill is in the fact that they need to be arranged in a way that makes them also look pretty. It's not easy."

Garden designers say the increasing threat of fire is also causing some widely used American garden features to fall out of fashion. According to Dave Egert, a part-time firefighter and presenter of the TV series The Coastal Gardener, white picket fences act like a "fuse" along which fire travels to a building. "You have to create a central space around your house, and reduce the amount of stuff that can fuel a fire," he said. "Use a patio, not decking. Have a lawn, not shrubbery. Keep trees away from the house."

In extreme cases, there have even been calls for the owners of houses most at risk from wildfires to be forced to fill their gardens with hard-to-burn vegetation. "I wondered why there was no code or law that requires developers and residents to use succulents in high-fire areas," Gary Lyons, a curator at the Huntington Botanical Gardens, told the Los Angeles Times. "Why should taxpayers shoulder the firefighting costs of a hillside development's incendiary landscape?"

Succulent plants also place fewer demands on dwindling water reserves. Ms Baldwin said early settlers planted succulents "because they didn't have automatic irrigation. So the gardens up to the 1950s were full of them".

Plants that can tame the flames

Krans aloe ('Aloe arborescens')

Originally from South Africa, this shrub-sized plant has become so common in the wild that most Californian nurseries don't even bother selling them. The sap can be used for alternative medicine, and its striking red flowers bloom in January.

Century plant ('Agave americana')

This fountain-shaped plant can be huge, but smaller versions are perfect for ornamental use. The "marginata" variant is prettier, with yellow stripes on its leaves. Flowers only occasionally, but it's worth the wait: its "spike" can reach up 25ft.

Foxtail ('Agave attenuata')

Unlike other agaves, this has no prickles, and owes its common name to the huge curved stem it develops when it flowers. The rest of the time, it resembles a giant green rose, with long tapered leaves that grow in clumps.

Red apple ('Aptenia cordifolia')

This provides terrific ground cover, and grows on banks and highway verges. It has pretty, red flowers around a green core, but is so common that many horticulturalists are reluctant to recommend it to clients.

Jade plant ('Crassula ovata')

Also a South African native, the jade plant makes an excellent shrub. Its small leaves are oval-shaped, and jade green with red edges.