Turfgrass expert offers tips to keep a lawn healthy during drought
Homeowners watching their grass turn yellow as drought drags on face a lot of potentially fateful decisions regarding the health of their lawns. Virginia Tech turfgrass expert Dan Sandor offered guidance as he answered questions about what to do and not to do for thirsty yards.
How can homeowners tell if their lawn is stressed from drought?
“There are many ways your lawn will ‘tell you’ when it’s thirsty and the soil is dry,” Sandor said.
- When you walk over the lawn and see footprints that remain on the surface — that’s a sign that it’s dry as the turf has lost its resiliency and ability to readily “bounce back” to its natural form.
- In some lawns you may see the area begin to “thin out” and leaf blades start to exhibit a twisting and curling pattern as the turf tries to reduce the amount of leaf area exposed to the sunlight. You may see the lawn begin to turn a blue-gray color and/or tan/beige color as well.
- With some turfgrass species, the lawn will turn straw-colored or brown, showing clear visible signs of drought stress. But don’t panic, as this is part of the magic of the turfgrass’s drought-resistance mechanisms. The plants are conserving their energy for a “return to normal,” and once irrigation and/or rainfall occurs, the lawn should begin to recover its normal green quality.
“An easy way to double-check is the old-fashioned screwdriver test. Stick a screwdriver about 3-4 inches into the ground, pull it out, and see if there’s any soil particles sticking to it. If there are none, the rootzone is dry. And if the soil is so dry and hard that you can’t get the screwdriver into the soil, that’s also confirmation!” he said.
What’s the best way to water during drought?
“With established lawns, you should try to water deeply but infrequently. This means applying a large volume of water using infrequent intervals — for example watering 0.33 inches twice a week or watering 0.25 inches three days a week. One important consideration for irrigating is that if you have fine-textured soils like a loam or clay soil, you will likely need to break up your irrigation application using a cycle-and-soak feature on your irrigation timer to avoid puddling and runoff,” he said.
What are common watering mistakes people make during drought?
“One is applying fertilizer — especially nitrogen — to alleviate drought stress. Fertilizer is essentially nutrients, like vitamins, for the turf and ‘force-feeding’ the grass isn’t what it wants while trying to survive a prolonged drought. It’s instead trying to rest and conserve as much energy as possible,” Sandor said.
“Watering too much is another potential mistake. While a homeowner may be inclined to water the lawn during drought conditions to ‘keep up appearances,’ many forget to adjust their schedule once the drought pressure has subsided and end up applying too much water after the drought has passed. Watering too much can also lead to diseases, especially if nighttime temperatures remain high and there is a lot of moisture remaining on the leaves and shoots,” he said.
Should you mow your lawn during a drought?
“During the drought you shouldn’t need to mow very often, but it’s important that whenever you do decide to mow, follow the one-third rule — never remove more than one-third of the leaf blade in a single mowing,” Sandor said.
“An important strategy to implement during drought conditions, and in the summer in general, is to raise your mowing height to a minimum of 3 to 3.5 inches — your grass will thank you for it as this helps alleviate some of the stress on the turf during the summer. If you can tolerate it, you should even consider raising it to 4 inches and/or just mowing on the highest setting on your mower. You’ll be surprised at how resilient your lawn is at the higher mowing height under drought conditions.”
About Sandor
An assistant professor in Virginia Tech’s School of Plant and Environmental Sciences, Daniel Sandor centers his research on best management practices for lawns including turfgrass establishment, cultivar selection, water-conservation strategies and irrigation technologies, and other cultural practices.
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