Seeding a Revolution

It was on one of those glorious, warm winter days in Austin that I made my way to the Lady Bird Johnson Wildflower Center, 279 acres of nature trails, savanna research plots and native plant gardens a few miles south of campus.

The center recently became a part of The University of Texas at Austin, and I was headed there to meet with Steve Windhager, Mark Simmons and Heather Venhaus, a team of restoration ecologists and environmental designers who are blazing new trails in native plant research and landscape design.

Deep green live oaks framed brilliant blue skies, light breezes pushed around the 70-degree air, and a mockingbird warbled an occasional off-season song.

The center was abuzz, but not with the billions of bees and butterflies one finds flitting around the gardens from spring to fall. The hubbub was created by the Wildflower Center’s people—ecologists, gardeners, volunteers and native plant enthusiasts—because a different kind of Texas native, a mountain lion, had possibly been sighted on one of the center’s miles of nature trails.

“How cool is it to have mountain lion?” exclaimed Venhaus, the Wildflower Center’s environmental designer. “It shows that all the contiguous pieces of property put together out here is a good thing. It’s working.”

She pointed to a map showing a green swath of land surrounded by a growing city and its suburbs, a wildlife corridor made by the Wildflower Center and other lands set aside by the City of Austin for aquifer protection.

Whether or not a mountain lion ever passed through the Wildflower Center property, the cat represented an idea that runs through the center like vines of trumpet creeper: that the urban and suburban environment of the city is not—and doesn’t have to be—disconnected from what we normally think of as “nature out there.” Windhager calls it the “take-only-pictures-and-leave-only-
footprints” kind of nature.

“The exciting thing about what we’re doing at the Wildflower Center is that we’re acknowledging that humans are a part of nature, that we have a role to play,” said Windhager, the center’s director of landscape restoration, “and that we can bring ecology into even our most inner cities and start doing good things for the larger ecosystem.”

Plants and the city

Windhager, Venhaus and ecologist Simmons have a revolutionary vision of what our urban and suburban spaces can be. They see cities as places where native plants and ecosystems should integrate seamlessly into the urban fabric, providing services for human inhabitants, like stormwater management, pollution filtration and landscape beautification, as well as necessary habitat and food for the area’s original inhabitants, like the birds and the bees.

The team is bringing their knowledge of and commitment to native plants to a slew of innovative research and consulting projects, from managing stormwater in large-scale urban developments to studying the effects of seasonal fires on Central Texas grasslands.

One of the strengths of their program, said Windhager, is the tight connection between practice and research, where implementing a project for a client can lead to a research finding and vice versa. “We’re actually learning a lot from our consulting projects that raise questions that then feed back into our research,” said Windhager.

Perhaps nothing highlights this better than the center’s recent green roof project.




Up on the rooftop

On the second floor of a Starbucks in southwest Austin not far from the Wildflower Center, coffee-sipping customers are treated to the view of a stunning roof covered by rows of native plants. The 8,000-square-foot extensive green roof—a first for Austin—was designed by Venhaus, who chose area natives like little bluestem and rock rose to cover the roof at Stratus Property’s Escarpment Village.

One advantage of choosing native plants to cover a roof that would have otherwise lain barren and hot is that the roof is now tied into the surrounding Edward’s Plateau and Blackland Prairie ecosystems. The roof is unlikely to ever attract a mountain lion, but it will certainly attract butterflies, birds and other wildlife. The plants themselves interact with their surrounding ecosystems, exchanging genes with their naturally occurring kin and dispersing their seeds.

“Native plants, as we’re finding, are a hugely untapped resource,” said Simmons. “We’re using native systems to solve specific problems rather than trying to bring in other plants and technologies. Rather than introduce a foreign grass, why not look at our own plant palette and see what we can use? The plants are adapted to the ecosystem and probably aren’t going to cause a huge problem, like becoming invasive. Every ecosystem has its own resources.”

The benefits of using a native green roof don’t extend to regional plants and ecosystems alone. Many innovative developers are turning to green roofs to save on energy costs (plants lower roof temperature by absorbing and reflecting the sun’s rays and transpiring), extend roof life, and help with stormwater runoff. Windhager said that, applied across an entire city, green roofs could have major impacts on the urban heat island effect and provide inner city habitat for other native species.

By most measures, the Stratus green roof project has been a great success, but the Wildflower Center team is not one to rest on its laurels. The project inspired a new longer-term research project at the center, where 24 chest-high miniature roofs have been constructed to study the success of various soil blends, roofing materials and native plants for green roofing.

On the day I visited, small tufts of Mexican feathergrass and Gregg’s salvia were waving in the breeze on the rooftops while an array of sensors measured things like water runoff and roof temperature. The roofs have been in place since August, and Windhager told me that up to 70% of the rainfall is staying on the roofs of some of the little buildings.




Drops in the barrel

The Wildflower Center’s green roof project is just a drop in the rain barrel.

Next to the green mini-roofs, Windhager showed off a series of square plots where he and his colleagues are measuring fertilizer runoff and monitoring weed growth among various turfgrasses. Most of the plots hold non-native grasses, but one verdant rectangle is carpeted in a native mix of buffalo, Texas grama and blue grama grasses. The turf looks so good and is performing so well that Wal-Mart executives have expressed interest in using it around their stores and funding further research into this grass mix.

Off-site, Simmons is working with landscape architecture firm Carter & Burgess to restore an 8-mile section of the San Antonio River just south of downtown. He’s also beginning to look at how urban prairies can be used to store excess carbon produced by cars and power plants.

Windhager’s work on Advanced Micro Device (AMD), Inc.’s controversial new corporate campus, which is being built over the Barton Springs contributing zone, will result in the largest rainwater storage system in the world (holding 1.5 million gallons) and the first 100% native landscape corporate campus in the United States.

Venhaus is working on a project to promote national standards for sustainable landscapes, much like the Leadership in Energy and Environmental Design (LEED®) certification available for green builders and architects.

Through these projects and many more, Windhager, Simmons and Venhaus are advancing Lady Bird Johnson’s original vision to promote the value of native plants. Their passion is contagious.

As I walked away from the center that balmy winter day, I didn’t catch a glimpse of any mountain lions. But I could begin to see how the folks at the Wildflower Center were slowly transforming our environment, doing their part to create a new kind of sustainable city for the 21st century.

Photos: John Langford