So when is the best time to water your lawn and why? Early morning or early evening are the best times to water your lawn because there is generally less wind and heat. Wind and heat account for the evaporation of water into the air. By watering in the cool still of the early morning or early evening you get greater penetration into the soil and less run-off.
While it’s true that watering your lawn is more cost effective when there is less water loss due to evaporation or wind, and those conditions are usually present at night, watering at night has its drawbacks:
- You won’t be as likely to notice problems with your irrigation system such as water runoff, poor sprinkler coverage or water breaks
- Grass stays wet longer at night and is more likely to become infected with disease (some diseases can develop in as little as two hours when a film of water remains on the grass!)
So how to take advantage of the optimum conditions but avoid the potential pitfalls? Shut the water off 30 minutes before sundown to give the grass time to dry.


