University of Illinois Extension

To Water or Not

Last years drought left many home lawns in dire shape. The number one question I’m getting right now is, “Should I water my lawn, and if so how much?” says Susan Grupp a horticulture educator with University of Illinois Extension, DuPage County. And that is a very good question. When the hot, dry weather arrives, each homeowner will need to decide if they want a green lawn, or if they are willing to let it go dormant.

If you prefer a green lawn, then you will need to make sure the lawn receives at least 1 to 1 ½ inches of water every 5-7 days. This means you will need to monitor the rainfall and provide supplemental water during dry weather.

For those people who don’t want to irrigate their lawns, they may choose to allow their lawn to go dormant. Keep in mind this means the lawn appears brown during hot, dry spells. Then in late summer or early fall, the lawn should recover and “green up” when temperatures drop and growing conditions improve.

But do not just forget about the lawn completely. If we have very hot dry weather again, be sure to apply 1/4-1/2 inch of water every 2-3 weeks. It is very important to do this, because the crowns and roots of lawn grasses should never be allowed to dry out. This little bit of water can make all the difference. In our county, many home lawns died in large patches because of our extremely hot, droughty weather last year and people did not understand they needed to supply this small amount of water.

Also, once you decide which watering method you’ll use, do not change your mind. For example, allowing the lawn to go dormant, and then watering to green it up, and then allowing to it go dormant again is very stressful to the lawn and can trigger additional problems.

Here are some watering tips if you want a green and growing lawn this summer:

  1. Choose a sprinkler that distributes the water in an even pattern and provides a uniform amount to the whole lawn.
  2. You will know it’s time to water your lawn if you can see your footprints. A well-watered lawn will spring back.
  3. Sunny lawns, south or west facing slopes and highly fertilized lawns will need more water.
  4. If you planted your lawn this spring, it is more vulnerable since the root system is not fully established and you may need to water more frequently.

Other things you can do to conserve water needs:

  1. Raise your mowing height.
  2. Do not apply quick release water-soluble nitrogen during hot dry weather.
  3. Keep your thatch level at ½ inch or less.
  4. Core-aerate in spring or fall to help improve soil compaction and root growth.
  5. Grow drought-tolerant grasses.