Up on the Rooftop

Austin designers of all disciplines often get opportunities to color outside the lines for clients. Rarer, though, is the chance to disregard the lines altogether—to truly go a little wild. Such was the luck of Rain Lily Design, a design and landscape company, when a Westlake Hills client commissioned the company to build a 38’x16’ rooftop garden project.

Though ubiquitous in New York City, structure-topping foliage is rare in these parts. Kim Beal, co-owner of Rain Lily Design, says she enjoyed the learning process and the challenge of bringing the client’s vision to fruition.

“The client was very informed, and had a great architect,” says Beal. “This was an intricately designed space from the beginning.”

The project’s architect—award-winning visionary Murray Legge of LZT Architects—is known for his love of unusual projects. “It was a cool project,” Legge says. “The roof is kind of vaulted, so the garden is hill-like—it echoes the surrounding hills. And it’s next to the pool, so it sort of looks like a whale rising up.”

Once the builders implemented Legge’s design, Rain Lily Design stepped in. “Because it’s a hill,” Beal notes, “there had to be a special system to keep the soil from sliding off.” The complex solution resembles a beehive with metal cables laced through plastic, creating individual cells to be filled with soil. The cells provide the proper tension to keep the garden intact.

“It was a challenge from a planting perspective because we’re filling each of these cells,” says Beal. “And we used a special soil mix that was the strangest I’d ever used—it included expanded shale, which holds water and slowly releases it to the plants.”

Beal notes that this type of project is definitely not a do-it-yourself one. Rooftop gardens, at least for now, remain expensive endeavors and require extensive planning.

Still, green-roofing is starting to gain more mainstream interest. “There’s some green roof at City Hall,” says Beal. “And a few architects are doing them now, though there’s not a ton of precedence.” She imagines a day when a rooftop garden kit will be a reality and more contractors will be knowledgeable in retrofitting older structures with up-above greenery. And aside from the aesthetic surprise and beauty of the gardens, there’s also an environmental benefit. “You’re offsetting your impervious cover,” says Beal, “and putting oxygen into the air. You’re also turning what’s dead and lifeless into a habitat.”

Working closely with the homeowner, Rain Lily Design successfully created an elevated Hill Country meadow using blue-gray sedge—a low-growing ornamental bunch grass, winecups, purple coneflowers and a multitude of their namesake rain lilies. “Butterflies and hummingbirds have already started to come to the garden we built,” Beal says proudly.

Rain Lily Design: 512-636-4430 or rainlilydesign.com.