The cloverleaf interchange a few miles north of downtown Washington, D.C., is already unique in that it’s the only one in the city.
Come next spring, it will hold another distinction, as one of its grassy spaces — the northeast quadrant — will be converted into the city’s first “low-mow zone.”
The city’s energy and environment department is piloting a project that could ultimately convert a “massive” amount of city-owned land, most of which is covered in traditional turf, into meadowlands that will provide habitat for birds, butterflies and amphibians, as well as save some labor and money. The spaces under consideration are the grasses in medians, on-ramps, right-of-ways and other chunks of land that are often not thought of much. But they still have to be maintained by the city, costing time, money and increasing carbon emissions.
Damien Ossi of D.C.’s environment department says a low-mow meadow could reduce city mowing of these sites to “once every couple of years.”
The project may be the first of its kind in a U.S. city. Many states have begun leaving their highway medians unmowed, especially after the latest recession drained state coffers. But leaving grass and weeds to grow unchecked is slightly different than what the District is planning, which is to kill the existing grass (currently, at the pilot site, by baking it under a tarp till spring) and intentionally plant native species. Even then, Ossi says, the city will likely have to mow the edges to preserve sight lines and keep the area looking nice.
There are a few precedents that may be relevant, though. A few years ago, Denver Water commissioned a report encouraging private property owners to turn their turf — yards, yes, but also parking lot islands, golf course roughs and corners of school campuses and office parks into native, sustainable landscapes. There, says Deborah Keammerer, a restoration ecologist and co-author of the report, the goal was water savings, not creating habitat, but the techniques — replacing water- and maintenance-hungry turf with local grasses and flowers — were roughly the same.
Keammerer says the water savings for one of these conversions can be huge. Depending on the type of grasses used to replace Kentucky bluegrass, landscaping departments can cut water usage in half — or stop irrigating entirely.
But it’s not all easy.
“The key thing when you’re dealing with public spaces,” Keammerer says, “is recognizing that maintenance is going to change. The bluegrass lawn is a pretty simple thing to maintain … and maintenance people understand conventional landscape maintenance.” Weed control is an issue — and crews need to be trained to recognize the difference between weeds and wild plants that sometimes have a weedy look.
“I think in some cases [a meadow] can have less maintenance, ultimately, [than turfgrass], but it’s smart maintenance,” Keammerer says. “You can’t just put it in the ground and think it’s going to be OK.”
The Works is made possible with the support of the Surdna Foundation.
Rachel Kaufman is Next City's senior editor, responsible for our daily journalism. She was a longtime Next City freelance writer and editor before coming on staff full-time. She has covered transportation, sustainability, science and tech. Her writing has appeared in Inc., National Geographic News, Scientific American and other outlets.