Monday, July 6, 2009

How Much Water Does Your Lawn Need?


During the Central Valley's hottest months (June through September), you may need to add an inch and a half to two inches of water to your lawn each week, divided into two or three applications. 
      The California Irrigation Management Information System can let you know what the current evapotranspiration rate is in your area of the state. This is a great way to pinpoint the exact amount of how much water is leaving your soil and lawn on a weekly basis, so you can adjust your sprinkler timing. This is a free service, but you have to register.

DO NOT WATER YOUR LAWN EVERY DAY! This practice can lead to serious lawn problems, such as shallow lawn roots (making the lawn more susceptible to drought and insect damage), fungal growths and diseases.

To determine how much water your sprinklers are putting out:

• Position 6 to 10 flat-bottomed, same sized containers around your lawn. Use drinking glasses, Tupperware, tuna fish or cat food cans; containers with taller sides will keep the water from splashing out. Put some in the greenest areas; put some in the areas that are struggling.

• Turn on your sprinklers for 30 minutes. Then, measure the amount of water in each container. There should not be more than a quarter-inch difference among all the containers. If there is, readjust or add to your sprinklers to hit those areas that aren't getting as much water. If, on average, you are getting a half-inch of water per container during that 30 minute test, then you need to water your lawn for two hours a week in the summer, to put two inches of water on your lawn. In this example, you would water your lawn twice a week, for an hour each time.

• You may need to adjust this timing if you see water streaming off the lawn. In that case, reduce the amount of time the sprinklers are on at any one time. Then, add a second cycle three or four hours later.

• It is best to water with rising temperatures, which in the summer, is from about 4 a.m. to 10 a.m. Earlier is better.


  1. I got a notice from Sacramento Suburban Water Dist. telling me to water my lawn between 9 am and noon. I have always tried to get finished before 9 am.

  2. I also have SSWD and they want me to water after 8 pm, when it is dark outside and there are mosquitoes (because of the West Nile virus we should not be outside this late in the day). This does not seem to make sense.