Quenching with Less

The grass gurus at CALS are coming up with water-saving practices for lawn care

Doug Soldat thinks there are better things to do with Wisconsin’s drinking water than use it to grow grass.

Nationwide, landscape irrigation sucks up about seven billion gallons of potable water on an average day—and probably two-thirds of that get sprinkled on home lawns, the CALS/UW-Extension soil scientist and turfgrass specialist estimates. Adding to the problem: We tend to all do it at the same time, particularly during hot, dry spells.

“The issue is reducing peak demand in municipal areas,” Soldat says. “As we put in more lawns and irrigation systems, we’re seeing higher peak demand, which means we have to build more wells and water towers.”

Soldat is looking at several strategies to address the issue. He’s got downspouts at the O.J. Noer Facility for Turfgrass Research flowing into the mother of all rain barrels, a 4,000-gallon underground reservoir that can see the center’s large lawn through a lengthy dry spell. He’s also developing guidelines for irrigating lawns with treated waste-water. That’s common in arid regions, and he suspects it will work even better in Wisconsin, where there’s ample rainfall to flush the soil of any salts the wastewater carries.

But one of the simplest solutions is to plant grass varieties that need less irrigation than, for example, Kentucky bluegrass, the most commonly planted grass in Wisconsin. One of the most promising, he says, is tall fescue.

“It has about the same water needs as Kentucky bluegrass, but its deeper roots give it access to more water in the soil,” Soldat explains. “It has double or triple the root mass of Kentucky bluegrass, so you could potentially double or triple the amount of time before you need to irrigate.”

Just how the two will match up during a dry spell is something Soldat is testing this summer. He’s growing several cultivars of each, along with a couple of other species, under severe drought conditions. That’s not easy in Wisconsin, where droughts are short and unpredictable. So he’s inducing drought with a rainout shelter—a 2,500-square-foot vinyl canopy on tracks. It sits off to the side when the sun is shining, but at the first hint of rain, it rolls into place to keep plots dry.

The drought tolerance work is part of a larger effort by the UW turf management team to provide information on reduced-impact lawn care strategies that work in Wisconsin. They offer suggestions in a new publication, “Organic and Reduced-Risk Lawn Care,” available at UW-Extension county offices or online at learningstore.uwex.edu.