University of Illinois Extension
Bruce Spangeberg

These articles are written to apply to the northeastern corner of Illinois. Problems and timing may not apply outside of this area.

Stateline Yard & Garden

Helping Lawns Through Summer Heat

June 24, 1999

June has showed us both the heat of summer and a stretch of pleasant, cool weather. Most likely, heat and perhaps drought will occur as we advance further into summer. Help you lawn through the summer by modifying your lawn care practices.

One simple way to prepare lawns for hot weather is to mow higher. Mow at heights around three inches or even slightly higher. If in doubt, set the mower as high as it will go. Grass maintained at a higher height of cut usually develops deeper roots and dries out slower than closely mowed turf. Even though most lawns are currently still growing at a rapid pace, growth will most likely slow down as the weather gets drier and hotter.

The other main concern of summer is watering lawns properly. With the heavy rains hitting most of northern Illinois in June, watering lawns is probably not on the minds of most homeowners! But remember there is plenty of summer yet ahead.

Cool-season lawn grasses such as Kentucky bluegrass, perennial ryegrass, and fine fescue naturally slow down and may go dormant in the heat of summer. Decide to water lawns all summer as needed to keep them green or let lawns go dormant. Do allow lawns to turn brown and then water them back to a green condition, as this depletes energy reserves and stresses the plant.

Grasses will start to wilt when drought stress begins. The lawn may assume an overall darker color. Footprints will remain after walking across the lawn. These are signals it is time to water.

Water lawns deeply and infrequently, applying about 1 to 1 1/2 inches per application, depending on site variables. Water early in the day if at all possible. Water should soak down into the soil.

If allowed to go dormant, lawns only need about 1/4 to 1/2 inch of water every two to three weeks to keep root and crown tissue alive. Once more favorable cooler and drier weather returns, the lawn should break dormancy and green-up again.

It's best to hold off until later in the season for most other lawn care practices, including fertilizing, seeding, thatch control, and applying weed killers. The period from late August through early September is ideal for many of these practices. For now, help your lawn by proper mowing, watering, and keeping foot and vehicle traffic off the grass as much as possible during the heat of the upcoming summer months.


Click here for the full article index