Watering twice a week is usually enough to keep a healthy lawn growing. In general, your lawn needs about one inch of water per week, including rainfall, to keep it green during the growing season. Water only when your lawn needs it, rather than on a set schedule. One sign that a lawn needs water is when it lacks enough moisture to spring back after you walk on it. If it stays flat, it's time to water.
When Should I Water?Water deeply and infrequently. Deep watering promotes a deep root system, while over-watering promotes shallow root growth, making your lawn less hardy.
- Following a heavy rain, skip your regular watering until the grass needs it.
- Delay regular lawn watering during the first cool weeks of spring. This encourages deeper rooting and makes your lawn healthier for the rest of the summer. It also delays the first time you have to mow the grass.
- If you have an automatic sprinkler system, check the heads periodically. Be sure they haven't shifted direction to spray water on the side of the house, driveway, or sidewalk instead of the lawn.
- More water is dispensed faster with a larger diameter hose. Sprinklers that throw large drops in a flat pattern are much more effective than those with fine, high sprays, which can be blown about and evaporated quickly.
- Don't water your lawn too much. An automatic system can be preset, but a sprinkler on the end of a hose needs your personal attention. Buy timer attachments that hook on between the faucet and hose, or set a kitchen timer to ring in 15 or 20 minutes to remind you to move the sprinkler to a new area.
- Not all soil is the same. If your grass grows on mostly clay soil, between 1/4 and 1/2 inch of water per hour can be absorbed before it starts running off wastefully. If you have sandy soil, you'll need to water more often and for shorter periods of time.
- Grassy areas on sunny southern sides of buildings or on slopes and areas near sidewalks and driveways need to be watered more often. Shady areas and northern exposures need water less frequently.
- Use root feeder or water-aerator probes around trees and bushes. Even for the biggest trees, you need go no deeper than 18 inches, while 8 to 12 inches is plenty deep for smaller trees and shrubs. The probes get water precisely where it's needed and simultaneously create lots of little holes that provide aeration benefits.