How Long To Water Grass, According To Experts

Drive through the neighborhood or the local park, and chances are you'll see the sprinklers in full force at various times of day, especially when temperatures increase. Lawn is known for being a water guzzler because it needs plenty of H20 to stay healthy. Yet leaving the sprinklers on for a long time doesn't mean it's better for the grass. Watering for too long, at the wrong time of day, or incorrectly costs money and wastes a precious resource. The way you water, how long, and when are all important factors that can ensure you're watering effectively and sufficiently to keep your turf green and your wallet happy. 

We spoke to lawn care experts for best methods and tips to keep your lawn healthy year-round. 

Know The Type Of Grass

The first step to knowing how to water the grass is knowing the type you have. "Grass needs water to survive and flourish, but how much water it needs and when is not always a one-size-fits-all solution—some types of grass require lots of water, others need less," explains Marc Mayer, director of technical operations at TruGreen. There are warm-season and cool-season grasses that are suited for different regions and weather. "Warm-season grasses—Bermudagrass, Zoysiagrass, St. Augustine, Centipedegrass— are well-adapted for hot, dry climates, and as such, have lower water requirements than species that thrive in cool, moist conditions," he explains. "A thorough watering of one to two inches—about the length of a house key—per week is usually sufficient to keep your warm-season lawn happy and healthy." 

Cool weather turf grows best in cooler temperatures and usually needs more water compared to warm-season grass. "Cool-season grasses—Kentucky Bluegrass, Perennial Ryegrass, Fine Fescue–generally have a higher water requirement than warm-season grasses as they have shallower root systems that are less efficient at absorbing water than species with extensive roots," says Mayer. He suggests watering around one to two inches a week. "Be aware that the amount may need to be adjusted if the lawn shows signs of moisture stress." 

How Long To Water Your Lawn?

The length of time you spend watering is also important. Aside from paying attention to the time, it can be hard to know just how much water is flowing from the sprinklers or hose. Want a easy way to know how much ½ an inch of water is? "A simple trick is to set out some shallow containers while you water and see how long it takes to collect about ½-inch of water," says Teri Valenzuela, natural science manager at lawn care company Sunday. "This can tell you how long you'll need for a watering session." 

How Much Water Does Turf Need?

The weather and time of year also influence how much water your turf needs. If it's during the rainy season, you'll likely need to water less frequently compared to several high temperature days. "Climate and season play big roles—hot, dry summers might require more frequent watering, while cooler, moist springs or falls may need less," explains Valenzuela.

You want to aim for 1 to 2 inches a week, which includes rainfall. If it's the rainy season or there's a spring or summer rainstorm, you'll need to water less to avoid overwatering your lawn. According to Valenzuela, "Each watering session should deliver about ⅓ to ½ inch of water to moisten the soil to a depth of about 6 inches, which supports healthy root development." 

Avoid Watering Daily

Experts recommend watering infrequently instead of daily. Watering the grass every day can create shallow roots, causing the grass to stress and not respond well if a drought were to occur. Watering less frequently means around one to two times per week, and according to Mayer, "trains roots to grow strong and more resilient to drought." 

Signs Of Overwatering And Underwatering

Figuring out how much to water your grass can have a slight learning curve to get it just right. Water too much or too little and the grass will suffer. "Make sure the water is distributed evenly across the lawn to avoid dry or soggy areas," says McCausland. Lawn will show signs when something isn't right and its care needs aren't being met. 

Underwatering

Underwatering occurs when you don't water enough. Unsurprisingly, it's more common in the summer when temperatures can be scorching. "To signal underwatering, your lawn’s elasticity will start to fade due to dehydration preventing it from perking back up, and footprints will remain after more than a couple of minutes," says Mayer. "This usually happens during the hotter months and is a good indicator that your lawn might be suffering from heat stress and could use a good drink to help it spring back." 

Overwatering

Lawn that is overwatered tends to stay wet and soggy. "Your soil will become saturated, wet, and muddy, and/or plants will begin to wilt despite excessive irrigation efforts," says Mayer. It's possible fungal diseases can occur if left unchecked. "You may even notice a sudden appearance of mold, fungi, or even a turf damaging disease," he says. The grass can thin out over time due to less oxygen in the soil and can potentially lead to root rot, Mayer adds. 

Stay vigilant with your lawn care to make changes as issues arise. This is easier to remedy than having a bigger problem to take care of. "Keep an eye out for these telltale signs and adjust your watering schedule accordingly if needed," says Mayer. 

When To Water

Choosing what time of day to water is fundamental, as it influences how much water you need and how well the water is absorbed. So when is the preferred time of day to water? "The best time to water is early in the morning, between 5 and 9 AM, when temperatures are cooler and there will be less evaporation," says Jason McCausland, national technical director for Weed Man, a lawn care company. Valenzuela adds that watering in the morning ensures there's sufficient time for the water to soak deep into the soil before the heat of the day.

Wondering why watering in the middle of the day isn't a good idea? "At midday, the water may evaporate too quickly before your soil absorbs the necessary amount it needs to thrive," says Mayer. "At night, watering grass may leave your turf susceptible to damage, as the damp blades can attract turf diseases." 

Irrigation System

Sprinklers, hose, or drip irrigation are options for watering the grass. The type you choose depends on the size of your lawn and whether you want to be able to program when you water. "Reducing water use in lawns is crucial," Valenzuela. "Installing a smart irrigation system or using a hose timer can significantly enhance watering efficiency." Make sure you check your irrigation systems to ensure they work properly and aren't wasting water. "Regularly check your sprinkler system to ensure it functions correctly and covers all areas of your lawn evenly," she says. "Investing in a smart sprinkler controller that adjusts watering based on local weather conditions can greatly improve water efficiency and lawn health."