Will Grass Die Permanently Due to Less Watering?

Basic Watering Guidelines

• Even a regularly watered lawn should dry out somewhat between soakings. Excess water can make a lawn more susceptible to summer fungus diseases, keep the roots shallow and vulnerable to drought stress, and make you spend more time mowing.

  New lawns should always be watered regularly for the first year, then gradually adapted to less frequent soakings.

  Knowing how far your water is penetrating into the ground is vital. Water for 20 minutes, then dig up a section of turf to see whether you've applied enough to soak 6 inches into the soil. Clay soils absorb water slowly but dry out gradually. Sandy soils let water drain through but quickly dry out again. Knowing the characteristics of your own lawn and the ground beneath it will allow you to make every gallon of water count.

Grass Types and Their Water Needs

• Grass dries out fastest when the weather is hot, the humidity low and the wind high. Buffalo grass and blue grama, however, can tolerate these conditions for weeks without additional watering. Bermuda grass, zoysia grass, St. Augustine grass and centipede grass, all warm-season grasses, are also quite drought-tolerant.

  Tall fescue has the ability to grow a deep root system that can tap into moist soil below most grasses, but in shallow soil it loses this advantage. Fine fescues tolerate periods of low water well and bluegrass will turn brown but recover by sprouting from the crown. Perennial ryegrass has little drought tolerance and may die quickly if water is withheld.

Increasing Drought-Tolerance

• Mowing high, 2 to 3 inches, and never removing more than a third of the length of the leaf blades will help improve the lawn's ability to survive dry periods. This may mean mowing more frequently since if you want a 2-inch-high lawn, you'll need to mow whenever it reaches 3 inches.

  Fertilize regularly to maintain adequate levels of phosphorus and potassium, essential for deep rooting and drought-tolerance.

  Water only when your lawn grass shows signs of stress, slight indications that it is close to wilting. This encourages the roots to go deeper and makes each application of water more effective. Be sure, however, to soak the entire root zone.

Testing for Water Stress

• A number of ways signal that a lawn is under water stress. The color of the grass may change slightly, becoming more bluish. If you walk across the lawn, the grass will stay bent wherever you stepped so that you leave footprints in the grass. Most reliable, of course, is digging down 6 or 8 inches to test the soil at the base. If the weather is very hot and windy, the grass blades may wilt even if water is available because they cannot bring it up from the roots fast enough to replace what they lose by evaporation.