How Long to Water Grass for a Lush Lawn—and How Often to Do It

When it comes to keeping your lawn lush, the question might not be “How much should I water my lawn,” but instead, “How long should I water my grass?” Trying to figure out the perfect timing will depend on a few factors, but in general, you’ll want to water your lawn between 30 minutes and an hour every week to get the greenest grass in the neighborhood.

How Long Should You Water Grass?

Aim to give your grass between an inch and two inches of water a week. That can mean running your sprinkler system (or the hose) anywhere between 30 minutes and an hour. Ideally, you’ll water the lawn in several short stints across the week. For example, water three times a week for 20 minutes for a total weekly watering time of one hour.

Figuring out exactly how long you should water your grass will require a little legwork. The first time you run your irrigation system, place a plastic container in the yard and set a timer. Once the water in the container reaches one inch, you’ll know how long it takes for your sprinkler system to deliver an inch of water to the lawn. 

From there, break up watering sessions across the week to avoid drowning your lawn all in one go. Too much water at once will essentially down a lawn, washing away any nutrients in the soil and weakening the root system. 

An easy way to check if your lawn is getting enough water is by soil saturation. The dirt should be moist up to six inches below the top layer. If you find the soil is dry between daily waterings, consider watering the lawn a few extra minutes a day. 

Factors That Impact Watering Time

While watering your lawn an hour a week is a good rule of thumb, other factors can influence how long to water your grass.

Time of Year

Grass may require more watering time during its growing season. 

Warm-season grasses, such as centipede and St. Augustine grass, grow best during the summer, when temperatures hover between 80 and 95 degrees Fahrenheit. They could be watered up to two inches a week during the summer. 

Cool-season grasses like ryegrass and fescue thrive in the fall and spring in cooler temperatures between 50 and 80 degrees Fahrenheit. You may need to water the lawn more during this time to encourage growth. 

Outside of their peak growing season, you don’t need to water your lawn as much or as frequently. That could be as little as 20 minutes every two weeks, depending on the type of grass and its overall water needs.

Type of Soil

If your soil tends to drain quickly and dry out more often, you may have to water your grass longer than an hour a week.

On the other hand, if your soil is slow to drain and you notice standing water or soggy spots, you might water it for less than an hour a week.  

Type of Grass

The type of grass your lawn has will also impact watering time. Warm-season grasses are often more hardy and can get by with as little as an inch of water during peak season. 

Generally, cool-season grasses need about 20% more water than warm-season grasses to thrive.

Sun Exposure

If the sun shines on your lawn for most of the day, you may need to water it more often as the grass can get dried out due to evaporation. However, if your lawn is shaded or partially shaded during the day, you may find you can go longer between waterings because little moisture is lost to evaporation.

Rainfall

If it’s a particularly rainy season in your area, note the estimated rainfall for the day and subtract that from your lawn’s weekly watering needs. For example, if a 1/4 inch of rain accumulates one day, water your lawn just 3/4 of an inch the rest of the week. To be exact, measure rainfall with a rain gauge. 

Age of Grass

Learning how to reseed a lawn? Freshly seeded grass or new sod will need notably more water than an established lawn. A lawn with new seed should be watered ten minutes twice a day. A freshly sodded lawn should be watered twice a day for 20 minutes at a time. Aim to water new grass on this schedule for a few weeks until roots are established. 

Watering Method

The method by which you water your lawn can be more or less water efficient.

• A classic hose and nozzle will get the job done quickly, but be careful with water pressure, as too much can damage roots or flood the soil. Aim to create a gentle mist or rainshower over the lawn instead of pressure washing the roots. Too much water pressure can drain nutrients from the soil and erode the root system. 

• A sprinkler system is very efficient with water and may mean you don’t need to water the lawn for long, depending on how much water your system emits. Set a timer to ensure the lawn’s properly hydrated and doesn’t get waterlogged.

• A drip irrigation system delivers water straight to the roots of the grass, but it might need to run longer than a hose or sprinkler system because of its slow release of water.

When to Water Your Grass

In addition to understanding how long you should water your grass, it’s important to know when to water it for maximum impact. Watering your grass during the hottest time of day could mean the moisture dries up before it even reaches the roots.

When the weather is 95 degrees Fahrenheit or hotter, it’s important to water your water during the cooler times, especially in the morning or evening, when the lawn isn’t receiving direct sun. That means running the sprinkler system or getting out the hose before 9 a.m. to avoid direct sunlight and high winds, which will allow more moisture to make it to the roots and soil.

An evening watering session should be between 4 p.m. and  6 p.m. If you water later than that, you run the risk of a wet lawn overnight, which can lead to fungal growth and pests. Watering in the early evening gives the grass enough time to dry out and drain before the sun sets and cool temperatures set in.

During the cooler season, the time of day is less important when it comes to watering your lawn. Just keep in mind the lawn shouldn’t be soaking wet when the sun sets. 

Tips to Keep Your Lawn Lush

Routinely Aerate Your Lawn

Figuring out when to aerate your lawn can help combat compacted soil. Experts suggest aerating your lawn every two to three years in the early fall.

Avoid Overwatering

If you regularly spot mushrooms or standing water in your yard, you’re likely overwatering the lawn, which can lead to dead patches.

Lawn Length

The ideal lawn length will vary based on the type of grass. The ideal height to cut grass is between two to three inches long.

Fertilize

Fertilizing your lawn can help solve dying patches or stunted growth by providing necessary nutrients. However, overfertilizing a lawn can do just as much damage as an under-fertilized lawn. An over-fertilized lawn can cause an imbalance, leading to dried out soil, salty soil that turns your grass brown and yellow. 

At most, you should fertilize your lawn twice a year. 

Tackle Weeds

Determine the best way to keep weed growth under control in your yard. Consider mulching, manually pulling them out, or using a herbicide-free solution to get rid of them.

Pick Up Waste

Dog poop is not good for your grass because it releases nutrients that can burn it. Letting Fido’s business sit on your lawn for days can lead to brown spots or diseased grass over time. Scoop the poop and toss it in the trash to avoid fungus growth, pests, and damage to your lawn.

Mow a Dry Lawn

If possible, avoid mowing your lawn when the grass is wet. It can damage the grass, the lawnmower, or even yourself, as the grass can be slippery. 

Dethatch

Notice dead grass piling up between the soil and new growth? When that thatch grows at least an inch thick, it’s time to dethatch your lawn to improve growth.

Overseed

Overseeding your lawn barely takes an afternoon, but it can help fill in bare or dead patches.