What it takes to make a sustainable landscape

The staff at the Lady Bird Johnson Wildflower Center at the University of Texas is not only developing a green landscaping rating system with its partners in the Sustainable Sites Initiative, it consults on sustainable landscape design, such as at the George W. Bush Presidential Center in Dallas, Advanced Micro Devices' Austin campus and San Antonio's Mission Reach Project.

Below are some steps for developing sustainable landscapes from the Center:

• A team of landscape specialists conduct an extensive pre-design site assessment that includes ecological history and an evaluation of soils and vegetation. Stakeholders provide input. The design considers the land's cultural significance, the need to provide gathering places for people and to minimize building footprints. Also important are trees and shrubs to shade buildings and land contours that capture stormwater for re-use.

• During construction, the upper layer of soil is carefully retained and re-used because it contains nutrients and microbes plants need. Equipment is restricted to certain locations because the vehicle weight compacts soil and hinders plant growth. Trees and plants that are removed may be stored and replanted. Underground tanks may be installed to capture stormwater.

• Because lawns are resource and labor-intensive, rock gardens and other features are used and a mixture of grasses native to the area replaces traditional turf grasses in lawns. Native lawns often require less water, herbicides and mowing than conventional lawns .

• A mixture of native and regionally adapted plants may dominate the landscape. Besides requiring less maintenance, these plants won't compete with wild-growing native plants for resources, as do some non-native invasive species. Insects and other wildlife often prefer native plants, so native landscapes provide better habitat for wildlife.

• Garden trimmings should be recycled. Mulch and other materials are obtained locally, avoiding the greenhouse gases produced by lengthy transportation. Stone or other materials removed on site are re-used as garden walls or other structures.

• Rainwater collected in barrels or tanks called cisterns is preferable to municipal drinking water for irrigation, because it saves water and energy. Driveways and walkways are constructed of material that allows rainwater to seep into the ground. Drip irrigation is more efficient than sprinkler heads. Features such as sunken vegetated areas or rock walls slow stormwater's movement across the land so soil can remove impurities before the water reaches waterways or storm systems.

To learn how to use eco-friendly landscaping, visit the Landscape for Life Web site created by the Lady Bird Johnson Wildflower Center at The University of Texas at Austin and the United States Botanic Garden. Or visit the voluntary Guidelines and Performance Benchmarks of the Sustainable Sites Initiative of the university's Lady Bird Johnson Wildflower Center, the American Society of Landscape Architects and the U.S. Botanic Garden.