Water Wise: When to Start Watering, Fertilizing and Mowing?

Image of water wise logoImage of Jim SchildBy Jim Schild, UNL Extension Educator
UNL Panhandle Research and Extension Center

When spring brings warmer days, it's tempting to watering the lawn and spread some fertilizer. But before you do that, take a moment to stop and think, a University of Nebraska-Lincoln Extension educator suggests.

"Once you get the grass green and growing, you're going to have to keep it green and growing, which means you'll have to continue watering it and mowing it," according to Jim Schild, Extension Educator at the Scottsbluff Extension office.

Bluegrass naturally puts on a flush of growth during the spring, Schild said. Applying fertilizer stimulates that natural flush and encourages more above-ground growth, which comes at the expense of the root system. For bluegrass to begin development above ground, it requires energy - which is stored in the roots. Growing greenery decreases the overall root system in the grass, Schild said.

Lawns that were fertilized last fall, Schild advises, don't need heavy fertilization in the spring. And the first fertilization need not be done until the end of April or early May. That application is typically a little fertilizer with crabgrass preventer.

Bluegrass will start growing when conditions are optimal, including soil temperatures in the mid-40s, according to Schild. Usually soil temperatures reach that point by early April.

Then it's time to think about water.

"Bluegrass will start greening up, and we want to make sure there is adequate moisture there for the grass to start growing," he said. To test soil moisture, try to push the shaft of a flat-head screwdriver into the ground. If the screwdriver will go in to a depth of 6 inches, soil moisture is adequate.

Schild said it's also tempting to mow lawns short in the spring. "That's okay with the first mowing to get the old dead grass off, but after that, mow at a height of 3 to 3 ¼ inches the rest of the season," he recommended.

Research shows that the taller the grass is mowed, the greater the rooting depth, according to Schild. Consequently, shorter mowing heights mean less rooting depth. If the grass is left longer than 3 ½ inches, the blades might flop over and mat down.

Schild added it's also important to make sure the mower blade is sharp to start the season off and sharpen it several times during the season. A dull blade can give the lawn a grayish cast and can also increase water use.

When mowing, follow the one-third rule: never remove more than one-third of the grass blade at one time.

"Basically, every time we mow we're losing a little bit more moisture because the grass blade is 90 percent moisture," Schild said.

The University of Nebraska Panhandle Research and Extension Center, the Nebraska Forest Service and the Cities of Gering, Scottsbluff and Terrytown, are working together to provide information on how to conserve water by using it wisely and the benefits that come from doing so.