The key to a healthy lawn
The key to a healthy lawn is to water deeply but infrequently. Deep and infrequent irrigation stimulates root growth, resulting in healthy, drought tolerant, and pest resistant turf.
Most lawns require between 1″ and 1.5″ of water per week. But the height of your grass can also contribute to water needs. A lawn maintained at 2-3 inches in height will hold more water than a lawn maintained at 1.5-2″ of height, which will be more subjected to heat stress in summer. Soil type also comes into play, since sandy soil holds water less effectively than a heavier clay type soil.
To determine how long it takes to water your lawn at the required rate, place several shallow containers such as margarine containers in different areas of the lawn for 15 minutes while irrigating. Measure in inches the depth of water from the containers. The average depth of water in these containers, multiplied by 4, is the inches of water per hour emitted by your sprinkler system. Then adjust your sprinkler timers accordingly. If you notice water runoff prior to achieving full irrigation, then you will have to water in a couple of cycles spaced at least half an hour apart to allow for complete penetration.
A lawn should be watered when the soil begins to dry out, but before the grass actually wilts. If you notice footprints in the lawn that don’t bounce back after you walk on it, or areas with a blue-green or smoky tinge, then your lawn is stressed. The lawn should be watered before these signs of wilting are obvious. You will find that most lawns, though, will need to be watered at least twice per week, usually less in spring and fall, and only during periods of extended dry weather in winter if your lawn doesn’t go dormant. Obviously, if your area is under water restrictions, do the best you can within those restrictions.