Summer Lawn Watering - U of I Extension

News Release

Summer Lawn Watering

This article was originally published on June 10, 2009 and expired on July 15, 2009. It is provided here for archival purposes and may contain dated information.

Watering lawns in the summer is common in many urban areas, states David Robson, University of Illinois Extension horticulture educator, Springfield Center.

Most turf species are cool season grasses and do not thrive during summer's intense heat. Bluegrass, ryegrass and fescues tend to go dormant, producing little leaf and root growth.

For the homeowner, this slow growth and light browning of the turf can be frightening. Thoughts of diseases and dead lawns are certain to arise. Yet, adds Robson, this is a natural survival mechanism for the turfgrass.

If drought conditions occur, lawns may brown completely. Leaf blades die, and some loss of roots occur. Grass crowns survive, though. Crowns are the swollen areas close to the surface where new blades develop and unfold. The area may be covered with dead leaf tissue, but close examination should reveal green growth beneath. When normal growing conditions resume in the fall, crowns will produce new leaves and shoots, returning the lawn to its traditional green lush look.

Water is crucial for the grass plant's survival. Even in severe drought, some water is necessary to keep roots and the crown alive.

Typically, an inch or two of water per week will keep most lawns looking green, provided the temperature is below 100 F. At higher temperatures, cool season grasses may require two to three inches of water weekly to maintain a green lush appearance.

Homeowners should be aware, however, that they are forcing a plant to grow during unfavorable conditions. Stress conditions are likely to occur, increasing the chances of diseases.

Robson adds that homeowners should remember to continue a regular watering habit once they have started. If turf receives irregular watering, it is likely to suffer. Forcing a plant in and out of dormancy reduces its vigor and increases the chances of diseases.

You can tell if a lawn needs watering by walking across it and noticing your foot prints. If the foot prints remain a half-hour later, the turf is under drought stress.

The best method to insure turf survival is to provide a half-inch of water every two weeks. Plants are likely to enter a dormant state. The water should be adequate to keep roots and crowns alive.

If regular watering is planned, make sure to irrigate heavily and infrequently. Light, frequent applications tend to promote a shallow root system that dries out quickly under hot, adverse conditions.

Water the lawns during the cool part of the early morning because less sprinkler evaporation occurs. Timers are available at many home improvement stores to water as the sun rises and before you get out of bed.

Apply at least a half-inch to an inch of water with each irrigation. Overlap sprinkler patterns to ensure uniform watering.

Several alternatives are available to reduce lawn watering. Warm season grasses such as Buffalo grass and Zoysia grass require less water and actually thrive during summer's heat. Woody groundcovers such as English ivy, vinca and euonymus Wintercreeper develop a more extensive root system and are able to withstand drier conditions. These groundcovers may be more practical in locations where homeowners have a difficult time maintaining turfgrass.

Source: David J. Robson, Extension Specialist, Pesticide Safety, drobson@illinois.edu

Pull date: July 15, 2009