For Release August 3, 1999

Lawn Watering IS Optional

by Chuck Otte, Geary County Extension Agent

The timely rains late last week and over the weekend were certainly a welcome break in the short dry spell we were experiencing. But it was quite obvious that there were a lot of people very worried about their lawns. Sprinklers were sprinkling away all over town. Sadly, there are far more myths about lawn watering than there are facts!

Most lawns in our area are cool season grasses, either Kentucky Bluegrass or Tall Fescue. They are called cool season grasses because they do most of their growing in the cool weather of the spring and fall. In spring they put on a rapid flush of growth and produce a seed head. In the fall they go through a slower but very luxuriant growth phase producing a lot of leaf area and root mass to store up food reserves for the winter and rapid spring growth.

If the weather turns off hot and dry, like it did the last half of July, these grasses go dormant. This is a normal reaction and how the grasses have adapted, over time, to survive short to moderate length droughts. Following a rain and subsequent cool down, like we had over the weekend, you can expect these grasses to break dormancy and put on new growth. This is the way that these grasses have grown and survived for a few hundred centuries.

Unfortunately, many homeowners have been led to believe that if they don’t keep that grass watered during these dry spells it will die. Do not confuse dormancy with death. If you pump enough water onto a cool season grass, it will stay green throughout the summer, even when temperatures reach 100 or above. This does put a certain stress on the grass and requires additional care and management However, the grass would be "happier" if it were allowed to just go dormant during these hot dry spells.

Too complicate the matter, many homeowners do not manage their lawns to be drought tolerant. The deeper the root system the more drought tolerant the lawn. To grow deep roots requires a lot of food. Leaf blades are the factory that produce that food. To maximize the drought hardiness of a cool season lawn you have to start with mowing height. Mow it as high as you can, preferably three to three and a half inches tall. The more leaf area, i.e. the longer the leaf, the more factory to produce the food!

I haven’t watered my lawn for close to ten years. Last week I had a few hot spots along the driveway and curb that went dormant. These have already started to green up and need mowing again. The longer leaf blade also gives you better weed control, and better weed control leaves more water for the grass. To further enhance root development, concentrate your fertilization in the fall, when the grass wants to develop roots anyway. Leave your clippings on the lawn. This thin mulch layer helps reduce water loss and, as it breaks down, gives a nice slow nutrient feed to the grass plants.

If the drought is extended to over a month in length, then a monthly deep soaking is helpful to keep grass plant crowns moist which prevents them from dying from dehydration. If you fell compelled to water your lawn do not apply a little water every day. Roots grow where there’s water and if the only water is in the top inch of soil then you will have a very shallow rooted lawn. Water once every five to seven days and apply enough water to soak the soil down 6 inches or more. This will encourage deeper rooted plants.

Nobody likes a long hot summer, especially a cool season grass. It is perfectly okay to let the plants follow their natural instinct. While your lawn may look dead, it’s only resting and while everyone else is sweating in the heat to mow their lawn, you and you lawn can wait for cooler weather to grow and mow!


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