How Green Is Your Garden? A New Rating System May Tell You

By Anne Raver
Washington, DC (January 8, 2009)- I couldn’t believe that the giant goldenrod was still blooming in late December, when the temperature was only 32 degrees. But there it was, its curvy seven-foot stems lounging in a landscape devoted to regional plants at the United States Botanic Garden here. Even in this frozen state, the garden serves as a model for the Sustainable Sites Initiative, introduced in November by the United States Botanic Garden, the American Society of Landscape Architects and the Lady Bird Johnson Wildflower Center.

The 179-page report, produced after three years of research by a diverse group of architects, landscape architects, ecologists, and engineers, includes proposed guidelines for creating sustainable landscapes, as well as diverse examples of successful restoration projects, from Point Fraser, in Perth, Australia, where a toxic wetland full of heavy metals now supports native plants and wildlife, to the Queens Botanical Garden, in Flushing, N.Y., where harvested rainwater feeds into ornamental water gardens, and gray water from sinks, dishwaters and showers is cleansed by plants and used to flush toilets.
The report also includes a point system for rating a landscape, much like the Leadership in Energy and Environmental Design (LEED) Green Building Rating System, which rates the sustainability of buildings. The LEED system, created by the United States Green Building Council, a private group of architects, engineers, builders, manufacturers and others, has been around since 1993. But its ratings – even platinum, the highest one, so sought-after by green builders- focus much more on buildings than on the land around them.
With the current LEED ratings, said Ray Mims, the garden’s conservation horticulturist and one of the leaders in developing the initiative, “you could get a platinum-certified building and potentially do a very poor job with the site. We want to make sure that you look at the soil, the vegetation, the hydrology, so that you are improving- or certainly not harming- the natural ecosystem,” he said.
Deon Glaser, a landscape architect on the staff of the council who helped write the initiative, said that LEED has requirements concerning landscape, which address issues like reducing runoff from buildings and barring development within 100 feet of a wetland. “But it doesn’t have specific requirements of how to do that,” Ms. Glaser said.
The initiative, on the other hand, goes into detail, specifying the kinds of plants, for example, that can be used to cleanse a disturbed wetland; how trees can be used to shade a building, protect it from wind, prevent erosion and clean the air; and what kind of plantings enhance mental health, draw people outside the building and even engage them in tending the landscape.
The Green Building Council “definitely wants to incorporate those aspects of green design and construction into LEED,” Ms. Glaser said. But that requires a long review process, she added, and a vote by the membership. Still, Mr. Mims said, “we’re hoping that it will be incorporated into LEED in 2011.”
In its efforts to be more sustainable, the United States Botanic Garden now sends all its green waste to the Department of Agriculture’s composting facility in Beltsville, Md., or to Pogo Organics, a commercial composting system in Sunshine, Md. It also recycles paper, cardboard, bottles and cans, and sends plastic pots to a center in northern Maryland where they are cleaned, ground up and sold to a plastics manufacturer.
But the 1931 conservatory and greenhouses at the garden’s production site, in southwest Washington, “are horribly inefficient,” Mr. Mims said. “Glasshouses, in general, are energy hogs.” The conservatory and greenhouses were conventionally engineered to funnel rainwater into storm sewers, rather than collecting it for irrigation, he said, “but now we’re looking at treating it as a resource.” Through a partnership with the Environmental Protection Agency’s Office of Water, the garden hopes to install a rainwater collection system within a year or two.
Related Resources:
New York Times- How Green Is Your Garden? A New Rating System May Tell You
Sustainable Sites Draft Available for Public Comment