In many areas of the country, watering the lawn isn’t as turnkey as turning on the irrigation system or setting out sprinklers. Many regions face water restrictions, and even markets with plenty are growing more mindful of water consumption. With increased awareness of our diminishing water supply, soaking the lawn on a hot summer day is just not a widely-accepted practice.
But all that doesn’t change clients’ desire for green grass. It does, however, alter the way customers want professionals to care for their properties. In response, turfgrass breeders are initiating trials that mimic drought conditions and scrutinize varieties’ performance with reduced water and fertilizer.
Their goal is to improve drought-tolerance of turfgrass so the landscape consumes less than natural resources but still lives up to traditional expectations. The result is a palette of turfgrass varieties that recover and green up following drought conditions. Some use up to 40 percent less water (others require even less) than typical turfgrass varieties.
“Turf is going greener,” says Jeff Wienkes, forage and turf specialist at La Crosse Seed, Madison, Wis. He encourages landscape contractors to consider varieties that bear a label from the Turfgrass Water Conservation Alliance (TWCA), which indicates that the turf type has met rigorous drought tolerance testing standards.
The main cost difference between the drought-tolerant turf varieties versus a “typical” grass is if the grass is a low seed yielder, meaning the company has to charge more per pound to cover the less seed per acre produced.
Seed researchers across the country today are more focused on providing green options that still meet expectations.
Rating drought tolerance.
So how do you determine a turfgrass species’ drought tolerance? The National Turfgrass Evaluation Program (NTEP) takes a two-pronged approach to testing turf for its resilience in low-water conditions. It performs trials in “rain-out shelter” environments, where turf only receives irrigation as needed or for limited periods of time. The turf’s decline and recovery are then rated, says Kevin Morris, NTEP executive director.
The second environment is a reduced irrigation model, a testing situation that mimics water restrictions in certain areas of the country, Morris says. Testing in different conditions is important because some regions, such as the east coast, may experience a “sudden, acute drought situation” with complete lack of rainfall. Other areas of the country are under constant drought stress and have water restrictions in place.
Aside from subjective analysis of turfgrass – basically, eyeballing its color and vigor – more objective digital imaging analysis is performed to identify exactly how resilient turfgrass is following simulated drought conditions. Imaging reveals a pixelated view of grass blades so shades of green are carefully analyzed. “We can see which ones are green, and which are browning out,” Wienkes says.
To receive a TWCA stamp of approval, a variety must use at least 40 percent less water than other varieties in its class. This doesn’t mean a variety is “plant it and forget it,” Wienkes says. But the label does give landscape contractors a guide for choosing turfgrass species that are proven to thrive with less water.
But subjective ratings are still important, Morris says. And so is feedback from local researchers who can cite which turfgrass varieties have proven effective in your region. “Each turfgrass species has its unique characteristics depending on location – they all have strengths and weaknesses,” he says.
Meanwhile, Morris reminds that considerations should extend beyond drought-tolerance to ensure choosing a variety that will meet clients’ expectations.
“There is a whole series of qualities that landscape contractors should look for, not just drought-tolerance, but the density, disease resistance and percentage of decline over time,” Morris says.
Choosing a turf type.
There’s no such thing as a single, drought-tolerant turf solution. When choosing a turf variety, landscape contractors must consider location, soil content, water and nitrogen requirements.
Be open minded when choosing a variety. “Everyone assumes that tall and fine fescues are the most drought-tolerant, but we have Kentucky bluegrass that can be winter-hardy and drought-tolerant,” Wienkes says.
Murray Wingate, turfgrass marketing and sales manager for Lebanon Turf Products, points out that Mid-Atlantic Kentucky bluegrasses tend to be more drought-tolerant than others in the same turfgrass family.
Wingate recommends seeking out “cutting-edge” varieties that are new to the market. “Those are the ones with the most recent breeding work in them in terms of how salt- and drought-tolerant they are,” he says.
Salt tolerance is a consideration for areas that receive little rainfall. Salt content in the irrigation water supply can impact turf vitality if the variety is not bred to manage in those conditions.
Regarding bluegrass, Morris says that this type tends to be even more drought-tolerant than zoysiagrass, but requires more fertilizer and mowing to maintain an attractive appearance.
Meanwhile, zoysiagrass does not generally like wet soil. The warm-season grass goes dormant during winter. “Homeowners and property managers have to understand that’s what they’re getting into with Zoysia,” Morris says, adding that homeowners should understand the appearance of a lawn in dormant state and opt for another variety if this does not suit their goals. Meanwhile, fine fescues’ wide leaves require little fertilizer and thrive in warm, southern climates.
“The area of adaption or usage of tall fescues has really spread. In areas that were traditionally Kentucky bluegrass (territory), the pendulum is swinging toward usage of tall fescues,” Wingate says. He notes that the northeast and upper-Midwest is beginning to use this turf type, which generally was planted in transition zone states.
Above all, be sure to communicate to clients how a turfgrass will look in drought-conditions, and what type of care is necessary. And look beyond drought tolerance, Morris says. “All of this is really a balancing act as far as what turfgrass to choose.”