Tips for Watering
Irrigation is the most important component of lawn maintenance. In order for a lawn to thrive, it must have a strong, vigorous root system. Roots need moist and aerated soil to grow properly. If, like so many others, you're determined to keep your lawn green throughout the growing season, here's what you need to do:
Water deep and infrequently
Deep and infrequent watering allow water to penetrate the top 6 to 8 inches of soil will promote healthy root growth. Typical lawns should receive at least one inch of water per week. It also maximizes water-use efficiency and turf-grass quality. Deep, infrequent watering produces a deeper, extensive root system, which enables turf to resist disease and stress. Light sprinkling is only beneficial for newly planted turf when the roots are developing in the very top portion of the soil. As turf is established, roots extend deeper into the soil. Light sprinkling will encourage root development only near the soil surface and stunt deeper root growth. Shallow root systems require frequent watering to keep the surface wet, creating an ideal environment for weeds and diseases.
Lawns need uniform coverage to maintain their vigor and a healthy appearance. Brown spots in a lawn are often due to uneven coverage. It is a good idea to regularly check irrigation systems for even coverage. To determine the rate at which your sprinkler system applies water to your lawn, place several small containers (about two inches deep) in the area being watered. Run the system for 15 minutes, see if the containers fill evenly, then measure the depth of water in all of the containers and average them. Multiply the average by four to determine how much water is applied to the lawn per hour. Adjust sprinkler heads to avoid dry or soggy spots.
Do not over water
Too much water is not only wasteful but can also increase turf growth, which requires more frequent mowing. Saturated soil can cause poor soil aeration and, as a result, weaken turf making it vulnerable to diseases and invasions of weeds. Not enough water can cause turf to dry out. Let the soil partially dry out between watering. Water when the top two inches of soil have dried out. Use an object such as a screwdriver to probe your soil and measure the depth of the moisture.
Irrigate only when your lawn needs water
In general, your lawn needs water when the top two inches of soil have dried out. If footprints remain visible after walking on the lawn or if the grass has changed color or has started to wilt, you have withheld too much water.
Irrigate early in the morning
The best times to water are between 4 a.m. and 8 a.m. in the morning. At these times, water use is most efficient, water loss from evaporation is minimal, and distribution is usually good because of good water pressure and limited wind. During the afternoon, water is wasted due to high evaporation rates. Do not water during the evening or pre-midnight hours because thatch and blades are susceptible to diseases, especially fungal diseases, if they are wet during cool nights.
Because there is so much variation among lawns, there is no one single answer for how much water to apply. Turf species, climate, and sprinkler output must be taken into account.
Get in the habit of watering every seven to 10 days during the growing season, maybe every three to five days in the middle of summer. Depending on your local water pressure and the type of sprinkler you're using, you may have to water for an hour to really soak the soil.
If you're trying to water a problem site, such as a slope or in soils that are heavily compacted, watch for runoff. To avoid wasting water, water the area a little bit until runoff begins, then stop, wait awhile, water again and repeat that process until the soil is thoroughly soaked.
Check your irrigation systems regularly to avoid water runoff or over-spraying, especially if the lawn is on a slope. Look for broken, tilted, or clogged sprinkler heads, and adjust sprinkler heads to ensure even coverage.