How Long to Water Your Lawn

By Amanda Lutz Updated February 5, 2024

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Jump to: How Long You Should Water | Established vs. Newly Seeded | Cool vs. Warm Season Grass | When to Water | How to Water with Sprinklers | How to Tell If Your Lawn Needs Water | Our Recommendation | FAQ

Just like humans and animals need water to stay healthy, your lawn needs water to absorb nutrients and maintain the green hue you’d expect. But determining when your lawn needs water and how much is challenging.

Overwatering a lawn can cause water to pool on your healthy lawn, drowning the roots of your grass and attracting pests, such as mosquitos. Underwatering your lawn can cause your grass to become brittle and dry and has its own pest hazards.

The fact is there’s no one way to water a lawn. The ideal watering schedule for your lawn may vary depending on factors such as your local climate and the type of grass native to your area. Read on to learn everything you need to know to water your lawn effectively.



How Long You Should Water Your Lawn

You should aim to water grass one to two times per week, adding about an inch of water each time you water. During some seasons, homeowners may need to apply up to one and a half inches of water each week to ensure their grass seed is getting the nourishment it needs.

The amount of water that your grass needs may vary depending on the type of grass you have and your local climate. Use the following methods to ensure your lawn gets enough water.

Do the ‘Can Test’

If you have a sprinkler system on your lawn, you can use the “can test” to determine how long you should run it to avoid over or underwatering. This method will tell you how long to run your sprinkler during your bi-weekly lawn watering sessions.

  1. Place an empty tuna can in an area where your sprinkler hits.
  2. Turn the sprinkler system on. 
  3. Watch the can and track how long it takes to fill with one-half inch of water.
  4. The length of time this takes is how long you should water once or twice weekly.

Use Your Sprinkler’s Data

Contact your sprinkler system manufacturer and ask for the system’s flow rate. The flow rate is calculated using the irrigation system’s gallons per minute. 

Multiply your lawn’s square footage by 0.62—that’s an inch of water per square foot of property your sprinkler heads cover. Then, divide this number by your sprinkler system’s flow rate to determine how long you should run your system to ensure hydration without excess runoff.



Established vs. Newly Seeded Lawns

The ideal watering schedule for your lawn will also vary depending on whether your lawn is newly seeded or established. 

Established Lawns

If your lawn is established, you’ll want to focus on keeping the grass’s deep roots moist but not soggy. Water deeply and infrequently—watering about 1 inch deep on each square foot of your lawn will be enough for most types of grass. Water twice weekly during most months of the year and increase to three times weekly as the temperature rises in the summer. Watering less often with more water helps your lawn strengthen its deepest roots, which also helps ward off weeds, disease, and pests.

Newly Seeded Lawns

If you’ve recently planted grassroots on your lawn, you’ll want to encourage them to develop a strong root system. However, when your lawn is still growing, watering with a sprinkler system can drown the seeds before they have a chance to take root.

After seeding, use a mister or spray bottle to spray newly seeded areas as often as is needed to keep the top 2 inches of soil moist. Be sure to consider local weather conditions when planning your watering schedule for a newly planted area.

Once you see grass blades sprout, reduce your watering to once daily until the grass reaches a 3-inch mowing height. At this point, you can resume your typical lawn care schedule and water the newly seeded area using the same method as the rest of your lawn.



Cool vs. Warm Season Grass

The best time to water your lawn and the amount of water to use might also vary depending on the type of grass that you have growing on your lawn. Most grasses are either cool-season grasses or warm-season grasses.

Cool-Season Grasses

Cool-season grasses grow actively during the cool fall months. During the cooler season, these grasses usually need an inch to one and a half inches of water each week. If you do not water cool-season grasses during a drought, they will go into dormancy early but will typically have no problem restoring a green color as soon as it begins raining again. Examples of common cool-season grasses include Kentucky bluegrass, tall fescue, and perennial ryegrass.

Warm-Season Grasses

Warm-season grasses grow rapidly when the temperature rises in the summer season. They require less water overall compared to cool-season grasses, as these grasses are drought-resistant and can survive for longer stretches of time between waterings. In the height of the summer, you may want to increase to three waterings daily. Examples of warm-season grasses include Bahia grass, St. Augustine grass, and Zoysia lawns.



When to Water Your Lawn Each Day

The time of day when you water your lawn can also help or hurt your landscaping progress. Try to water your lawn between 4 a.m. and 6 a.m. each day. If you cannot water this early, try to sneak a watering in before 10 a.m. Watering during the cool early morning hours allows your grassroots to absorb the water before evaporation occurs.

If you cannot water during the early morning hours, water between 4 p.m. and 6 p.m. Do not water during the evening. Though it is cooler after the sun sets, allowing water to sit on your lawn overnight can cause your grass to become more prone to disease.



How to Water Your Lawn Automatically with Sprinklers

Automatic sprinkler systems can provide a simple way to keep your watering schedule on track. You’ll see the following few common sprinkler systems as you compare your lawn care options.

No matter which type of sprinkler system you use, be sure it is not pointed at a sidewalk or other public area where it may spray pedestrians.



How to Tell Your Lawn Needs Water

While overwatering your lawn can lead to several lawn diseases, underwatering can also cause problems. Some common signs that your lawn is not getting enough water include the following:

Take a short walk across your grass to test if your lawn needs water. Examine the areas where you’ve left footprints, and track how long it takes for the footprints to disappear. If they linger for more than a few seconds, your lawn needs water, as the individual grass blades are not strong enough to spring back after impact.

Testing the soil compaction with a screwdriver can also tell if your lawn needs water. Grab a screwdriver, and attempt to insert the tool 6 inches into the earth. If you can’t push the tool at least 6 inches into the ground, it’s time to water your lawn.



Our Recommendation

You should give your lawn about 1 inch of water each week. Split your waterings into two or three individual sessions, increasing the number of waterings and the amount of water you use during your grass’s growing season. If you need a bit of assistance keeping your lawn looking green and gorgeous, consider working with a professional lawn care service such as TruGreen.



How Long to Water Lawn FAQ

How long should I run my sprinklers?

You should run your sprinkler system for as long as it takes to apply a half inch of water to your lawn. You will need to water for at least 10 minutes per week for most systems. Measure your sprinkler system‘s output to ensure you’re not using too much water or underwatering. 

What is the best lawn watering schedule?

The best lawn watering schedule begins with an early morning watering, ideally between 4 a.m. and 6 a.m. Morning watering helps ensure that your grass has a chance to absorb the water before it evaporates. Twice weekly will be enough to keep most types of grass happy and healthy throughout the year. 

How do I know if I’m overwatering my lawn?

If your lawn feels spongy to the touch or your feet sink into the earth when you walk on the grass, chances are high that your lawn has been overwatered.