Even if you’re watering your lawn the recommended amount once or twice per week, it’s also very important to know how long to water it for.
The amount of time your lawn is being watered will directly determine the amount of water that it receives, and it is vital to get this right.
If you’re watering your lawn deeply, once a week (as is recommended), then you need to give your grass approximately 1 inch of water (or 2 inches, depending on the grass type). So what you need to figure out, is how long it takes for your sprinkler to provide around an inch and a half of water, and then that should be the amount of time it is left on to water the lawn.
To figure it out, you can leave the sprinkler on, aimed at a can or container. Measure it so that you know when the water gets to one inch. Obviously, you need to be timing this process, so that you then know how long it took, and apply it to your grass watering habits.
(Take into account, that during the summer season you will need to water the grass a bit more, so leave the sprinklers on for a little extra time! And the contrary applied to the winter seasons, or during rainy weeks.)