The warmer weather is fast approaching (woo-hoo), and you're probably wondering how often you should be watering your lawn in summer. A deep watering once a week in summer is usually enough, provided the watering is a deep one. It's best to saturate the lawn using a sprinkler for about an hour or more - this will ensure the water gets in deep and it will encourage the roots to follow the water down and grow deeper, making your lawn more drought tolerant.