The Definitive Guide to Watering your Lawn

The definitive guide to watering your lawn

A healthy lawn is a properly watered one. While this is hardly an earth-shattering revelation, knowing how often to turn on the sprinklers — let alone when and for how long — is easier said than done. Allow us to demystify some of the particulars so you can maintain vivid, green grass.

The basics

First thing’s first: it’s important to remember that lawn care is a year-round process. Your grass needs at least 1 to 1.5 inches of water a week, even in the winter when the sun seems to disappear for months at a time. Your grass will need more water in the summer, when the higher temperatures lead to more evaporation. And remember that rainfall counts as water for your lawn, so be careful not to overdo it with the sprinklers when you get precipitation.

You’ll also want to determine your soil type, as this affects both how much and how often you should water. To do so, you can buy a soil test kit or consult a lawn care professional.

As for when you should be watering your lawn, the earlier in the morning the better. Watering in the morning helps you conserve water, as the cooler temperatures mean less evaporation. What’s more, you’ll want to avoid having wet grass at night, as this can lead to fungus and other issues over time.

It’s better to water your lawn every few days rather than every day. And while lawns with clay soil can get away with one watering per week, sandy soil does best with watering every third day. For soils that require multiple waterings per week, waiting a few days between sessions allows a lawn’s root system to grow deeper, which helps the grass retain water longer, and also protects it against diseases.

To deliver an inch of water to your lawn, it takes a sprinkler system roughly an hour. To get a more exact idea of how long you should leave the water running, lay empty tuna or cat food cans on your lawn, run your sprinklers and time how long it takes until there’s an inch of water in the cans. For soil that does best with three waterings per week, you’d divide that time by three and set your irrigation timer accordingly.


There are plenty of ways to diagnose your lawn’s condition and to measure whether your yard is getting adequate water. One method is the so-called screwdriver test: You’ll know your lawn’s getting enough water if you can easily stick a screwdriver 6 to 8 inches into your soil. Here are some other tips for easily assessing your grass.

Signs your lawn needs more watering:

  • After walking across your lawn, you can clearly see your footprints in the grass.
  • Your grass turns from vibrant green to a duller, bluish-gray color.
  • Some leaf blades start to wilt.

Signs your lawn is getting too much water:

  • Water from your sprinkler system runs into the street and down the gutter. (This might also mean that you need to adjust your sprinkler heads.)
  • An overwatered lawn can sometimes display the same symptoms as an under-watered one, so be sure to check if it feels damp before turning on the sprinklers.

Sarah Silbert