If you’re feeling guilty about having a mostly green lawn, here’s some news that could ease the guilt and even make you feel a bit noble.
Jim Baird, a turf expert with UC Agriculture and Natural Resources, says letting your lawn die is not good for the environment. Lawns help clean the air, keep temperatures low and provide food and home for wildlife.
“People have gone from one extreme to another,” Baird said in a media release. “When we weren’t in a water crisis, people were watering seven days a week, 365 days a year. Now, people feel like they’re doing the right thing by putting no water on their lawn at all.”
Baird, a turf specialist with the Cooperative Extension at UC Riverside, says you can maintain an attractive lawn with minimal water. Maintaining a lawn, he says, is much better than letting it die or replacing it with synthetic turf, concrete or even drought tolerant plants.
Artificial turf absorbs heat and on a hot day, your fake lawn can reach 180 degrees. To cool it, you need to water it down. Bare soil, concrete and asphalt also get hot and hold the heat longer than a grassy lawn, which functions like a natural evaporative cooler.
“The more we let our grass lawns die or go away,” Baird says, “the hotter it’s going to get.”
Like all plants, grass plays an important role in absorbing carbon from the atmosphere and holding it in the soil, a process that scientists say is important for slowing global warming. Our lawns also provide food and habitat for birds, small mammals, insects, spiders and worms. The lawn alternatives — artificial turf, concrete, asphalt and hard-packed earth — do none of those things.
Those dead patches of hard ground also can add to pollution through water runoff. Properly maintained turfgrass is porous, allowing water to filtrate into the ground. Those hard surface cause the water to sheet off into storm drains, carrying soil and other things into the waterways.
Baird, who has had a long love affair with green expanses, says he’s dismayed by the sight of so many dead and dying lawns, deaths that he calls unnecessary. The massive reduction of so much irrigated land is a short term ecological loss, he says, but when the drought ends, which it surely will eventually do, it will be difficult and expensive to revive them.
“A dead lawn could come back as nothing but weeds,” Baird says.
Baird and his colleagues have written an eight-page publication on managing turfgrass under drought conditions that will help homeowners and lawn managers keep their lawns alive with minimal water.
The publication outlines the concept of deficit irrigation, a system in which the grass has just enough water to maintain an adequate appearance, but with less growth. Irrigation can be cut back to two times per week. If the blades spring back after being walked on, the lawn doesn’t need more water.
“The grass may not be as lush and green as usual, but you can still have a lawn where kids and pets can play and families can enjoy outdoor barbecues,” Baird says.
Additional water savings can be achieved by carefully managing the sprinkler system. Areas shaded by trees or a house need less water than grass with day-long sun exposure. Irrigating before dawn reduces evaporation, leaving more water for the plant roots to absorb. Using sprinklers when there is less wind will help prevent overspray onto sidewalks and the street.
“We suggest homeowners test their sprinklers by placing cans around the lawn and running the sprinklers to see if water is being applied uniformly,” Baird said. “This also provides the opportunity for them to see if there are any broken sprinklers or leaks that need to be repaired.”
Mowing practices also impact the lawn’s water use. The grass should be maintained at the tallest height recommended for the species being grown to encourage development of deep roots. Leaving the grass clippings on the lawn with a mulching mower will reduce evaporation from the soil surface.
If new lawns are being considered, water use can be cut by selecting a turfgrass species that uses less water. For example, Baird is studying kikuyugrass in plots at UC Riverside Turfgrass Research Facility. A native of East Africa, kikuyugrass is well adapted to warm, temperate climates in coastal areas and inland valleys of Southern and Central California. Other drought-tolerant grasses being studied at the facility are Bermudagrass and seashore paspalum.
For professional landscapers and home gardeners interested in detailed turfgrass research information, UC ANR is hosting a Turfgrass and Landscape Research Field Day Sept. 17. Registration is $90 before Aug. 28, $100 on or after Aug. 28 and $120 onsite. The complete agenda, registration form and previous research reports can be found on the website.