Once the rainy spring season is over and the summer heat arrives, you might start to worry about how long to water your lawn. It can be tough to figure out how much water your lawn needs and exactly how often to turn on the sprinkler. Rainfall in your area, temperature and irrigation are all factors that can impact how often during the week you need to water and for what length of time. However, there are some basic guidelines that you can use to help you determine how long to water your lawn.
In order for a lawn to stay looking green and healthy, it is recommended that it receives around 2.5 cm/1inch of water each week. However, you don't want it to receive that entire amount of water at once. It's better for your grass to receive its weekly ration of water divided over a few days. An example would be to perhaps give your lawn 1/3 inch of water on Monday, Thursday and Saturday. Make sure to leave time in between watering to allow the lawn to dry.
In general, you don't want your lawn to receive much more than the suggested one inch of water each week. Overwatering makes it more difficult for your lawn to develop deep roots and can lead to other problems such as weeds growing in the grass. One way to help prevent overwatering your grass is to test how long it takes your sprinkler to distribute an inch of water. Place a cup outside, and run the sprinkler for around 15 minutes. Then measure how much water is in the cup. If your cup has 1/3 inch of water inside it after 15 minutes, you'll know that you need to run the sprinkler for 45 minutes each week to equal one inch of water.
Check with your city to find out about specific water conservation guidelines and lawn watering restrictions in your area.