As the weather starts to get warmer those of us with lawns are facing an important decision on whether or not to irrigate our lawns. Most of the lawns in Illinois are planted with cool-season grasses like bluegrasses, ryegrasses and fescues. These grasses will slow their growth and may go dormant once it becomes hot and dry. These grasses generally need around 1 to 1 ½ inches of water per week in order to maintain active growth and maintain green color.
If you decide to let your lawn go dormant it is important to let it remain dormant. Don’t let the grass turn brown (enter dormancy) then water it enough to green it up and then let it go dormant again. Breaking dormancy requires a large amount of energy. By repeatedly allowing grasses to go dormant and then breaking that dormancy, will drain the food reserves of the plants. This will stress the plants and make them more susceptible to disease and insect problems. They won’t be able to compete with weeds as well either.
If you decide to water your lawn throughout the summer here are some tips:
- Do not begin watering at the first sign of warm weather. Allowing grasses to go under mild drought stress will cause them to grow deeper roots.
- To determine when to water, walk on your lawn and see if you leave visible footprints behind. Lawns that need water will not spring back and lawns that have adequate water will spring back and you won’t be able to see footprints.
- When watering make sure you are supplying a uniform amount of water to the entire lawn. Don’t let some areas get to much water and others not enough. If you are using a sprinkler or sprinkler system, place containers with straight sides, such as a coffee can, in various places in your lawn. Measure the amount of water captured by each container and overlap the sprinkler patterns if needed in order to get a uniform amount of water to the entire lawn.
- Water as infrequently as possible. When you do water, water lawns thoroughly so that moisture goes deep into the ground.
- Coarse, sandy soils will require more frequent watering than fine-textured clay soils. During hot, dry, windy, and sunny conditions lawns may require more frequent watering as well.
- Newly planted lawns (both seeded and sodded) may need more frequent watering. They have much smaller root systems than established lawns.
- Water lawns early in the day. This will help reduce water loss due to evaporation and will help reduce the incidence of disease.
If you decide to water you lawn it is important that you continue to do so throughout the summer. If for some reason you decide to stop and let your lawn go dormant, let it remain dormant.
For more information on lawn care visit University of Illinois Extension’s LawnTalk website at http://urbanext.illinois.edu/lawntalk.