When Is the Best Time to Water Your Grass?

lawn sprinkler watering the grass

If you long for that lush, healthy, green lawn, watering your grass the right way at the right time will make all the difference. So when is the best time to water your grass? 

A proper watering regimen involves knowing how long, how often, and how much to water your grass. Luckily, our guide can help you achieve the best lawn on the block.

When should you water your grass?

hand watering using a hose

The best time of day to water your grass is between 5 a.m. and 9 a.m. when there is less wind and evaporation. This allows the water to penetrate the soil and reach the roots. It also gives the excess water left on the foliage time to dry quickly, which reduces the risk of fungal disease

Your next best option to reduce the likelihood of evaporation is watering in the early evening, around 6 p.m. However, when you water at night, excess water can sit on the grass blades for hours without the sun to dry it, possibly causing brown patch fungus, melting-out, and dollar spot, to name a few.

If you must water in the evening, a drip irrigation system can help. It targets the grassroots directly without touching the foliage, reducing the risk of disease. Even so, morning watering gives your grass the best chance of growing and staying healthy.

Pro tip: Try not to water your lawn in the heat of the day between 10 a.m. and 4 p.m. During this time, most of the water will be lost to evaporation before it can soak into the soil, wasting water and leaving your grass thirsty. 

How long should you water your grass?

It typically takes about 30 minutes to accumulate half an inch of water, which is how much you should water the lawn during each session. If you want to determine exactly how long it takes your sprinklers to accumulate this amount, use the tuna can test

  • Step 1 – Place small, shallow containers around your lawn, such as empty tuna cans.
  • Step 2 – Turn on your sprinklers and set a timer for 30 minutes. 
  • Step 3 – At the end of the 30 minutes, measure the amount of water in each can with a ruler. Find the average amount of water across all the cans, and that’s about how much water your sprinkler supplies in 30 minutes.  
  • Step 4 – Adjust your watering time according to the results. If you found the average amount of water in each can was about half an inch, you’re good to water your lawn for 30 minutes each session. If the average was less than half an inch, you’ll need to leave the sprinklers on longer. If it was more, you’ll need to turn them off sooner. 

How often should you water your grass?

automatic garden lawn sprinkler
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Since it takes about 30 minutes to accumulate half an inch of water, water your grass two to three times a week for 30 minutes each time to reach the ideal of 1 to 1.5 inches. The soil should be moist, about 6 to 8 inches deep. 

Remember that the required amount of water includes natural precipitation. If you get heavy rainfall several times a week, you may only have to water your lawn once, if at all. Stay on top of the weather and adjust your watering schedule as needed.

It’s essential to water your lawn less often but for longer periods. This method encourages the grassroots to search for moisture, resulting in a robust and deep root system. In contrast, watering too often for short periods promotes a shallow and weak root system that can’t withstand drought.

How to water your grass effectively

To get the most out of your time spent irrigating, keep these tips in mind:

Water according to grass maturity

Although established grass doesn’t require much water, new grass is a different story. In a newly seeded cool-season lawn, the top 1.5 inches of soil should be kept moist (not soggy) for five to 10 days, which is how long the germination period lasts. If you have warm-season grass, you may have to water the new seeds for up to two or three weeks, depending on the type.

Water new grass seeds once or twice daily with a gentle spray or mist to prevent displacing the seeds and flooding your lawn. Use a light touch and stay consistent in your watering.

Water according to season 

How you water your grass also depends on the season and the weather conditions. For example, during your region’s rainy season, you’ll need to cut back on how much water you’re giving your grass. During periods of drought, you’ll need to water your grass more. 

The temperature also affects how much water your grass needs. In summer, cool-season grasses will go dormant unless they get lots of water because they don’t handle heat very well. 

On the other hand, in the cooler temperatures of early spring and late fall, you should water your grass less (regardless of grass type) because less sunlight and heat mean less evaporation. You don’t want too much water on your lawn to attract fungi.

Water according to soil type

person testing the soil quality
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Soil types fall into four categories: loam, clay, sand, and silt. Each retains and drains water differently, but loam is considered the healthiest, most fertile type and is a balanced mixture of all the other types.

Clay soils are known to hold water well – almost too well. This is because clay particles are extremely small and form a compact layer that doesn’t allow water to escape. To avoid runoff and pooling, watering sessions should be shorter – around 15 minutes – and more frequent until you reach 1 to 1.5 inches of water in a week. This gives the soil more time to absorb the water. 

Sandy soils absorb water well but drain quickly, thanks to the large size of the particles. Give soil high in sand ⅓ inch of water three times a week. 

Silty soils are prone to erosion, so you must be especially careful not to overwater. In terms of water retention, they tend to drain better than clay soils but less quickly than sandy soils. Water silty soils twice a week with ½ inch of water each time. 

Loamy soil combines sand’s drainage qualities and clay’s water retention qualities. Lawns with loamy soil need about ½ inch of water twice a week. 

If you don’t know your soil type, get a soil test with your local extension office. It will tell you the texture of your soil and what amendments could be used to improve it. 

Pro tip: To test your soil’s moisture levels, press the tip of a screwdriver into your soil. It should easily penetrate the first 6 to 8 inches of soil. If it’s hard for the screwdriver to break through the soil, that means the soil is dry, and you should adjust your watering schedule accordingly. 

Water according to grass type

sprinklers in flower beds
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Think of your grass type when calculating how often and how much to water your lawn. Whether your grass is warm-season or cool-season, its needs will need to be considered. 

Cool-season grasses typically require 1 inch to 1.5 inches of water weekly. Water three times a week in equally spaced intervals. They may need even more water during summer to prevent dormancy. Some common types include:

  • Kentucky bluegrass
  • Fine fescue
  • Tall fescue
  • Perennial ryegrass
  • Bentgrass

Warm-season grasses need less water than cool-season grasses, which is typically about ½ inch to 1 inch of water weekly. Water any of the following types once or twice a week:

  • Bermudagrass
  • St. Augustinegrass
  • Zoysiagrass
  • Centipedegrass
  • Bahiagrass
  • Buffalograss

Pro tip: Some of the most drought-tolerant grass types are Bermuda, centipede, buffalo, and tall fescue.

FAQ about watering your grass

What is the best irrigation system to conserve water?

A drip irrigation system can help you significantly reduce water waste. These systems disperse water slowly and at the plant’s root zone, where plants need it the most to develop healthy, deep roots. Installing an automatic system can further help you reduce your water bill.

What are some other ways to conserve water?

Landscaping with native plants, adding hardscapes to your yard, xeriscaping, installing artificial turf, or planting groundcovers are effective ways to protect the planet and conserve water. All approaches are low-maintenance and require minimal or no watering.

What sprinkler system is best to water your grass?

Sprinklers are not a one-size-fits-all solution. The sprinkler that is best for your yard depends on its size and shape, water pressure, and soil type. See our article on the different types of sprinklers to learn which one is best for your needs. 

When is the best time to water other plants?

The best time to water your garden, whether it’s a vegetable garden, flower bed, or container garden, is the same time you water your grass – in the early morning.

Garden plants face the same challenges as grass when it comes to watering, including water loss from evaporation and the risk of fungal diseases from overwatering. 

Why is it important to monitor my lawn?

Like any living organism, your lawn requires monitoring to ensure it stays healthy. If your grass appears squishy, limp, yellow, or brown, or you notice signs of moss or algae, it’s time to revise your watering schedule. Overwatered or underwatered grass also bounces back much slower after mowing or walking on it.

Instead of giving your grass a set amount of water on a schedule, it’s best to let its needs guide you. As soon as you see signs of stress, change your approach and try again.

Hire a pro to help

Meeting your lawn’s water needs requires commitment, time, and effort. On a hot day, you would probably prefer to be at the beach or pool instead of determining the best time to water your grass. 

To that end, we can connect you to a lawn care pro in your area to manage all your lawn care needs so you can do what you love and still have the best-looking lawn on the block. 

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Andie Ioó

In my free time, I enjoy traveling with my husband, sports, trying out new recipes, reading, and watching reruns of '90s TV shows. As a way to relax and decompress, I enjoy landscaping around my little yard and DIY home projects.