British imports

LONDON — SOMETIMES you have to travel halfway around the world to solve a problem in your own backyard, a point Southern California gardeners may want to note as they face drought, limited water supplies and air pollution, not to mention threats posed by encroaching development, invasive plants, synthetic pesticides and fertilizers -- our list of woes goes on and on.

For some welcome solutions, look to none other than the Chelsea Flower Show, arguably the world's finest garden exhibition, held by Royal Horticultural Society in the heart of London.

Although you might think of English gardens as flowery borders and clipped hedges, the May show proved England's position as the center of progressive gardening. The event featured close to 50 display gardens, some nearly a quarter-acre large, and most created by Europe's leading landscape designers. Sustainability was the unspoken theme, broadly interpreted and elegantly executed. Though the spaces were created for Chelsea, the concepts and philosophies spoke directly to California.

The ultimate in sustainable design and winner of best-in-show was "600 Days With Bradstone," a stunning combination of the ancient and the futuristic, designed by Sarah Eberle and sponsored by the hardscape company Bradstone. Eberle spent eight years researching what she calls a "terrestrial space garden" that would support an astronaut for an extended stay on Mars. That may sound far-fetched, but many of the concepts apply to any homeowner looking to create an interesting, environmentally conscious space despite challenging natural conditions.

Eberle's garden was enveloped in rammed earth walls whose strata of red, burnt orange and copper were embedded with aggregate. The idea was to emulate walls formed using materials from the red planet's metal-rich rock surface. The wall also created a primeval backdrop that set the mood.

The designer chose some plants as a food source, others for medicinal purposes and still others because they would contribute a significant amount of oxygen to the atmosphere. Most nonedible selections were drought-tolerant because, Eberle realized, the only way to get water would be to extract it from the permafrost.

To manage such a limited resource, she clustered plants into distinct zones based on water needs, a practical technique whether on Mars or Mount Washington. Eberle created a "working" area of the garden with essential crops -- squash, tomatoes, kale and other dietary basics -- along with luxuries such as olives, figs, grapes and pistachios, all requiring a fair amount of water. Medicinal plants including calendula and opium poppy were placed here as well.