Management practices in the fall and spring determine the drought tolerance of the lawn in summer. To reduce the need for irrigation, your lawn management program should maximize root volume and depth in preparation for summer drought. By the time summer rolls around, there is little you can do to help a lawn except mow and irrigate properly.

The following lawn care tips will help reduce the need for irrigation and increase the chance of surviving summer drought.

• Avoid the temptation to irrigate in spring just to get grass growing. Allow it to green up naturally. Mow frequently and avoid scalping. Do not begin to irrigate until dry conditions of early summer cause obvious turf wilt that lasts for more than one day.
  In the spring, atmospheric water demands are low and moderate wilting of turf does not damage the lawn. If in the spring the soil is allowed to dry slightly and the grass to wilt some, a deeper and more hardy root system will develop. Such a root system will be necessary to reduce the need for summer irrigation and to survive drought conditions or when city water restrictions are imposed.

• Mow grass as tall and as frequently as possible with a properly sharpened blade to produce a dense cover with a deep root system. Taller grass has a deeper root system that draws moisture from a larger volume of soil and results in less need for irrigation.
  Grass height should never be less than 2-1/2 inches after mowing. Mow frequently enough so that clippings are 1 to 1-1/2 inches long. Raise the mower height if grass has grown too tall since the previous mowing. A lawn mowed at heights of 3 to 3-1/2 inches will have a better chance of surviving prolonged drought and water restrictions.
  Most homeowners mow lawns once a week regardless of the mowing height. Taller mowing heights are less likely to cause turf scalping, especially when grass leaves are rapidly growing in the spring. Dull mower blades and scalped turf result in an unattractive lawn that too many homeowners try to correct with over-irrigation.

• Apply nitrogen fertilizer to cool-season grasses (Kentucky bluegrass, tall fescue and perennial ryegrass) primarily in the fall.
  Some nitrogen may be applied in the spring if the lawn is sparse and bare soil is visible. Avoid summer application of nitrogen. Nitrogen fertilizer applied in the spring and summer causes additional leaf growth, which uses stored plant energy that normally would be used to produce roots needed for water uptake during summer.

• Test the soil to ensure an adequate amount of phosphorus and potassium. Additional applications of potassium -- one pound of K₂O per 1,000 square feet -- in April and again in May or June will also improve the summer performance of lawns.

• Core aerify tight soils and thatched turf in the fall or spring to increase water and air movement into the soil. This builds better root systems. Avoid summer coring in the absence of water, since it may cause excessive drying and drought stress.

• Limit thatch removal by power raking or verticutting to fall or early spring or fall, since water demands are low and turf recovery is rapid. Do not severely power-rake lawns in the late spring or summer or they will require excessive irrigation to remain alive. When necessary, severe power raking and seeding should be done in September.

• Select grasses that require less summertime irrigation to remain attractive. Zoysia is a warm-season grass and tall fescue is a cool-season grass. Both are noted for the ability to make an attractive summer lawn with less irrigation.