This Is the Best Time to Water Grass, According to Lawn Experts

Homeowners may have various opinions on what the "best yard" looks like, but there’s often one common goal: a lush, green lawn. It’s no secret that water is essential if you want to attain grade-A grass, but there’s more to it than turning on the sprinkler. When you water your lawn is an important factor in its overall health and appearance. Ahead, we talked to two lawn care experts to find out when the best time to water grass is and some other tips to help you land the title of best lawn on the block.

When Is the Best Time to Water Grass? 

The best time to water your grass is in the early morning hours, according to both experts we spoke with. George Burger, owner of George Burger & Sons, Inc., a landscaping supply store and garden center, suggests 5 to 6 a.m. as the sweet spot.

Craig Elworthy, founder of Lawnbright, a lawncare subscription service, echoes the early morning approach. "The best time is going to be just before dawn," he says, adding that if you water later in the day, "some of [the water] will evaporate, and the sun's rays are going to penetrate the first inch or two of the ground," leading to water waste and a less than satiated lawn. 

But what if you don’t rise before or even with the sun and don’t have an irrigation system on a timer? Burger says the watering window closes by around 10 a.m. Both experts also noted that your lawn should get between 1 and 1 ½ inches of water per week. 

Water deeply and infrequently, says Elworthy, limiting your efforts to a few times a week versus every day.  Short and frequent watering may get the job done, but Elworthy says this leads to short roots that spread laterally instead of growing deep into the ground. When it’s hot, that can lead to fried and dried-out roots. "You want to put down about a half to an inch of water each watering session, and what that's going to do is going to tell the roots that, hey, there's water to be had, but it's down deep, away from where the surfaces where the soil is cooler, in a way, from the sun's rays."

When to Avoid Watering Grass 

In general, you want to avoid watering your lawn after 10 a.m. After that, the sun's rays work to evaporate the water faster, and less water penetrates the grass, making your efforts far less effective. Here are other times when you may want to reconsider your watering strategy.

In the Evening

You might think you can water your lawn in the evening after work if you miss the morning window, but think again. "Evening watering is a timeframe you want to avoid if at all possible," says Burger. "When you evening water, that means the turf is going to stay damp and moist, which then starts to create the perfect environment for diseases to set in." 

In the absence of sunlight to aid in evaporation, the grass remains wet for a longer period. Burger points out that there are natural spores in the environment, including on our grass. That moist environment can aid in spore growth and spread, leaving your lawn vulnerable to a host of turf diseases, like rust, which is indicated by yellowing grass, the likes of which may leave the soles of your shoes (or feet) yellow after walking through. Another common fungal disease, says Burger, is red thread, which is more common in bluegrass and manifests as grass with a pinkish-red hue. 

Before Mowing

You should never water your lawn right before you plan to mow it (nor should you mow it immediately after a rainfall). "Never mow when it’s wet. You’re going to be tearing the grass blades," says Elworthy, adding that this also leads to clumps of wet grass building up under the mower deck and then on your lawn, which is never good for growth. 

When Your Grass Goes Dormant 

Maybe you live in an area with watering restrictions or went on vacation only to return to a yellowing lawn. Your inclination may be to go heavy on the water, but Elworthy says that’s not the best approach. "Just let it go dormant," he says, noting that it’s going dormant to protect itself and will come back in the fall when there is typically more rain. In the meantime, Elworthy recommends making sure your lawn gets about ½ inch of water every other week. This should be enough to keep the crown of the grass, or the part of the plant that connects the blades of grass to the roots, alive.  

Things to Consider When Watering Grass 

Watering your grass in the early morning is best regardless of where you live or what type of grass you have, but there are other factors that you should think about while you're watering your lawn.

Grass Type 

Both Burger and Elworthy note that the type of grass you have will directly impact how much water you need. For instance, Kentucky Bluegrass requires more water than some other types, like draught-tolerant Tall Fescue. If you’re planting grass, always take note of the watering requirements for the variety you choose. If you aren’t sure what type of grass you have, take note of its characteristics and compare it to the types common to your region. You can also consult a lawn care professional or take a sample, including the roots, to an expert who can help you identify it. 

Rainfall Amount

Your lawn doesn’t care if water comes from a hose or the sky. Keep current rainfall in mind when watering your grass. How can you strike a balance between your watering efforts and rain patterns? "What you can do is get a rain gauge for your irrigation system, if you have an irrigation system," says Elworthy. If you don’t have a rain gauge, Burger recommends getting a couple of sprinkler gauges and placing them around your yard. "Every week, you want to be making sure that you're filling that up one way or the other, whether it's through rainfall or with a sprinkler of some kind," Burger says.

If you live in an area prone to heavy but quick rainfalls, however, don’t assume they’ll yield the proper amount of water. According to Burger, a sizable rainfall in a short period may not meet your lawn’s needs. "Nice soft, gentle rains where it rains for several hours—those are the most beneficial rains," he says. "They come down, and the soil can absorb it and keep sucking that water up, Rather than downpours, where the top half inch gets wet, but everything else runs away." 

Soil Type

Some soil will soak up water faster than others. Burger recommends lawn owners become acquainted with the type of soil they have so they can better adapt their watering needs, including how long it needs to be watered. "To thoroughly get an inch of depth penetration, you need to let a sprinkler run for at least 45 minutes," Burger says.

But, he cautions that soil can vary. If it’s loamy soil, where the water can soak up and penetrate faster, watering can be reduced to e a 30-minute session, he says. "Here in NEPA [Northeastern Pennsylvania], where we’re more clay-based, it takes a while for the water to penetrate."

Sun Exposure 

Water will quickly evaporate on hot summer days. If your region is experiencing a stretch of high temps and sunny days, you may need to give your lawn a little extra water.  The pattern of the sun in the context of your yard can also dictate how much water your lawn needs, according to Elworthy. "Areas of your lawn [that get more sun] are going to need more water," he says. "So those are going to be closer to an inch and a half a week.” Areas of your lawn that get more shade and don’t get dried out by the sun likely won’t need as much.