Purdue News

August lawn care requires little effort, Purdue expert says

Although there is less to be done, the yard work never disappears completely. Here are Reicher's recommendations for what needs to be done for a healthy lawn in August:

Fertilization

August is not a good month to apply fertilizer, but it is a good month to head to the nursery or hardware store to buy fertilizer for September.

According to Reicher, applying fertilizer in August can damage turf, causing leaf burn or death of the plants, and it can stimulate some turfgrass diseases. It is better to wait until mid-September to apply any fertilizer.

In mid-September, apply one pound of nitrogen fertilizer per 1,000 square feet of lawn. It is best to select a fertilizer that contains about 50 percent slow-release nitrogen. This is usually in a form such as sulfur or polymer-coated urea, urea formaldehyde, or natural organics.

"Even if you do nothing else for your lawn other than mow it, consider applying fertilizer in September," Reicher said. "You'll be surprised at the results this fall and next spring."

Irrigation

To properly water a lawn, wet the upper 4 to 6 inches of the soil during each irrigation. Watering early in the morning (between 3 a.m. and 8 a.m.) is most beneficial to the lawn and most efficient in terms of water use, Reicher said. Do not repeat the watering until the grass shows signs of drying out, such as an off-green or blue color, or wilting.

If the lawn is not watered, the turf will go dormant and turn brown during dry periods. Although this may be unattractive, the turf is not dead. The lawn should recover after the next substantial rainfall.

"A turf stand can survive in a dormant state for about four weeks without substantial thinning of the turf upon recovery," Reicher said. "If dry conditions persist, do a thorough watering about once every four to five weeks to help ensure survival of the grass."

On dormant lawns, Reicher said, it is important to avoid walking on the grass, because this may kill it. Also, a homeowner must decide whether to let the lawn go dormant or not. "Don't let your lawn turn brown, and then water to turn it green, and then let it turn brown again," Reicher said. "Either water enough to keep the lawn green or let it go dormant."

Mowing

In some parts of Indiana, ample rains have fallen and lawns continue to grow at a moderate pace, Reicher said. In these areas, it is important to mow regularly so not more than one third of the grass leaf is cut at any one mowing. "You are better off mowing too frequently than not frequently enough," Reicher says.

In areas that have received too little rain, Reicher said, it is important to not mow turfgrass that is suffering from drought stress. "If you do, it will damage the crowns of turf plants and leave brown mower tracks well after the lawn greens up again," he said.

During the hot summer days, it is best not to mow in the mid-afternoon when the lawn might be under drought stress. Rather, wait and mow in the early evening or early morning during cool temperatures, which will minimize the stress on the turf.

Grub Control

Grub damage often occurs in lawns in August, and most commonly it is found in lawns or areas that have had grub damage in the past. The small, white grubs are the larvae of Japanese beetles and masked chafers. If the lawn has more than four to six grubs per square foot, consider applying an insecticide in early August. Be sure to water thoroughly after application to move the insecticide down to the grubs.

Reicher said there is also a nonchemical alternative to controlling the grubs. "If you find grubs but don't want to apply an insecticide, irrigate more frequently to help the turfgrass outgrow the damage. This should minimize the damage but probably won't eliminate it," he said.

More lawn and turf information, including weekly updates by Purdue turf experts, can be found on the Internet at http://www.aes.purdue.edu/agronomy/turf/turftips.htm

Source: Zac Reicher, (765) 494-9737; e-mail, zreicher@dept.agry.purdue.edu
Writer: Steve Tally, (765) 494-9809; e-mail, tally@ecn.purdue.edu
Purdue News Service: (765) 494-2096; e-mail, purduenews@purdue.edu

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