A certain amount of lawn may be aesthetically unavoidable in some projects; Williams used it in the Palm Beach Minimal Project to break sightlines, for example. “But the days of grassy lawns in California are pretty much over,” Lewis says.
Selecting the right greenery alone does not make a garden sustainable. Landscaping is also important, especially when it comes to managing water retention and runoff. Stone pavers and gravel, for example, rather than concrete or sidewalk slabs, create permeable surfaces that allow stormwater to seep into the ground.
For a project in Napa, Lewis used cobblestones atop a bed of gravel to create trails. These low heat index stones reflect heat, keep the space cooler, and allow water to immediately return to the ground. Where the previous garden contained tough privets and sod, drought-tolerant ornamental grasses and rosemary now soften the serene space.
In Palm Beach, Williams used a 12-inch loose pebble strip around the building’s foundation to keep the house clean in heavy rains and to help the garden absorb water. For Marmol Radziner, the solution is to break up slabs with gravel or plantation strips, as was the case with a project in Beverly Hills. “As modernists we tend to use a lot of concrete walls and slabs,” says Radziner. “We have to allow the water to come back into the earth.”
Few municipalities require homeowners to collect stormwater — yet — although this is an important factor in any landscape considered. During the SSA project in Massachusetts, a rainwater garden even became the organizing principle of the site’s design. Today, wetland irises fill a garden framed with reclaimed granite, where guests’ children play and catch frogs. Whether a customer requests it or not, SSA typically incorporates stormwater harvesting or biological gullies (drainage courses designed to remove silt and pollution from storm water) into their designs. “This is driven by our desire to be respectful of a site,” says Stimson.
Whether driven by economics or aesthetics, trends in sustainable gardens are spreading. The best designers prove they don’t have to trade luxury and beauty for environmental responsibility. Of course, any successful garden has to work with the physical world, not against it. But when it comes to sustainable landscapes, as Radziner succinctly puts it, “we are creating an improved version of nature”.