"Green" seals of approval are slapped on dishwashers, heat pumps, light bulbs and entire buildings. So why not the outdoors?

As of Thursday, even open-air spaces — from parks and parking lots to corporate and college campuses — will have their own environmental rating system.

"The recognition of the need to address climate change and sustainability is going up and up," says Nancy Somerville, CEO of the American Society of Landscape Architects, who worked with the U.S. Botanic Garden in Washington, D.C., and the Lady Bird Johnson Wildflower Center at the University of Texas-Austin to create the first national rating system for sustainable landscapes.

Until now, the most comprehensive guidelines and sought-after environmental ratings were for buildings. A Leadership in Energy and Environmental Design (LEED) certification by the U.S. Green Building Council can qualify builders and cities for tax credits. Now that the nation is embracing all things green to save money and natural resources, a LEED rating also brings marketing cachet to a project.

The spaces around buildings now can earn similar recognition from the Sustainable Sites Initiatives' new star rating scale (four stars is the highest).

"It can be the site and landscaping around a building," Somerville says.

The rating will measure several criteria. They may include planting trees in a parking lot or paving with permeable materials to minimize heat and storm-water runoff. Or landscaping with native plants to reduce maintenance, irrigation and use of pesticides.