Summer Irrigation for Lawns
by Don Janssen, Extension Educator
How much water does a lawn need? In general, cool-season grasses need about one to 1.5 inches of water per week to maintain green color and active growth. Factors such as the soil, weather, and management practices all have a role in water needs of lawns.
Decide before summer to either water lawns consistently as needed throughout the season, or let lawns go dormant as conditions turn warm and dry. Do not let the grass turn totally brown, apply enough water to green it up, and then let the grass go dormant again. This actually drains large amounts of food reserves from the plant.
The first few warm days of summer does not automatically mean to water lawns heavily. In fact, allowing lawns to start to go under mild drought stress actually increases rooting. Watch for footprinting, or footprints remaining on the lawn after walking across it. Grasses also tend to turn darker in color as they go under drought stress.
Water as infrequently as possible. Water thoroughly so moisture gets down to the depth of the roots. Exceptions to this general rule would be for newly seeded lawns where the surface needs to stay moist, newly sodded lawns that have not yet rooted into the soil or when summer patch disease is a problem.
Water early in the day. Avoid frequent waterings that promote shallower root systems and weeds. Place coffee cans or similar straight-sided containers on the lawn to help measure water application rates. Avoid flooding areas, or missing other spots. On heavy clay soils and slopes, watch for excessive runoff; it may be necessary to apply the water in two applications to assure it soaks in.
To conserve water use, mow higher, avoid excess nitrogen as warm weather approaches, limit traffic over the lawn and avoid pesticide use on drought stressed lawns.
University of Nebraska-Lincoln Extension in Lancaster County is your on-line yard and garden educational resource. The information on this Web site is valid for residents of southeastern Nebraska. It may or may not apply in your area. If you live outside southeastern Nebraska, visit your local Extension office