WATERING

The single most important requirement for germinating turf grass seed is adequate moisture. Keeping the seed damp, either by rainfall or irrigation, will encourage proper seed development. The first watering can be done right away. It should moisten the soil to depth a of two to three inches. The first waterings should be done carefully as not to apply the water with such force that it washes away soil or dislodges the seed. Irrigate the newly seeded area lightly and frequently two or three times daily, until the grass begins to establish and mature. Later the intervals between waterings can be lengthened and the amount of water applied at any one time can be increased.

Effective Watering Practices

Frequent lawn watering often encourages shallow rooting and may predispose the lawn to increased disease and greater susceptibility to stress injury. Watering deeply and less frequently provides for improved turf growth and increased water conservation compared to light, frequent watering.

Water deeply when necessary

• Water early in the day so foliage will dry up quickly.
• Night watering is not recommended during hot, humid weather because of potential for disease development.

When is irrigation necessary?

Many variables influence the amount of water used by turf grasses. These include:

• Humidity
• Temperature
• Grass species
• Rate of growth

Rooting depth and soil texture also affect turf grass water needs. More deeply rooted grasses can extract water from a greater volume of soil and are subsequently more drought tolerant than shallow rooted species. Finer textured soils hold more water than course soils and require less frequent irrigation. Because so many factors interact to determine turf grass water use, it is difficult to give a general estimate of how often to water a lawn. The best technique for determining when to water is to observe both soil and plant conditions and then water accordingly.

It is occasionally necessary to provide supplemental irrigation to keep turf grasses growing well, especially during the summer months. Water is lost from the soil by gravitational drainage, evaporation, and plant use. If plant or soil water content becomes limiting, drought stress and/or turf grass death may occur.

Detecting Wilt and Drought Stress

In order to conserve water and avoid the detriments of over watering, lawns should be watered just prior to the development of wilting and drought stress. Wilting occurs because the plant's internal water contents drops so low that the plant cannot remain turgid, and plant cells begin to shrivel. Turf grasses undergo a series of visible changes when they begin to wilt. The development of a bluish-green coloration and the rolling or folding of leaf blades are signs associated with wilting. If footprints remain visible on the lawn for several minutes after walking on it, this means the turf is not very turgid and wilting is imminent.

These initial symptoms of wilting will not cause permanent injury to the lawn. However, they do indicate that the lawn should be watered soon in order to avoid drought stress and possible turf grass death. In addition to observing plant symptoms, examining the soil is helpful in determining when to irrigate. Use a soil probe or garden spade to examine the soil to a depth of approximately six inches. If the soil appears dry, it is time to water.