Is running a sprinkler for 30 minutes too long? Irrigation pros share their rules of thumb for watering

Key Points

• The ideal sprinkler run time varies between 10 minutes and 90 minutes depending on the type of sprinkler you have.
• Suggested sprinkler run times will also vary based on your region, your soil, grass type, and more.
• Overwatering your lawn can cause disease due to shallow roots, soil erosion, and lack of nutrients.

It’s great that sprinklers and irrigation systems make watering your yard virtually hands-free, allowing you to tackle other important tasks while your grass gets the moisture it needs—especially when it’s too hot to stand outside with a watering can or hose. That said, sprinklers shouldn’t be set-it-and-forget-it systems.

Don’t find yourself setting the sprinkler timer incorrectly or accidentally overwatering your lawn. Running a sprinkler for 30 minutes and calling it a day isn’t the best idea for your grass, and here’s why.

Meet the Expert

• Don Chouinard is the current Contractor Sales Manager at Irrigreen with over 30 years of experience in the irrigation industry.
• Justin Wilson, licensed irrigation pro, is the owner of American Irrigation Repair in Georgetown, Texas.
• David McCary is the owner of Seattle Sustainable Landscapes, a full-service landscaping company.

How Long Should You Run a Sprinkler in Your Yard?

The right amount of water for lawngrass (and the right amount of time to water) is somewhat of a moving target.

“The goal is not a fixed number of minutes but delivering the right amount of water,” Don Chouinard, Contractor Sales Manager at Irrigreen, says. 

Experts agree that established lawns should receive about 1 inch of water per week during the growing season. This includes rainfall and any supplemental watering you provide. When it comes to running your sprinkler, Chouinard says aiming for a 1/2-inch of water per session is ideal.

So, what does that look like in terms of run times? It depends on your sprinkler type.

“Fixed-spray heads and pop-up nozzles deliver water quickly,” Chouinard says. “They usually need shorter run times, 10 to 25 minutes per session, to apply a solid half-inch [of water].”

In contrast, rotating heads and rotors often require 30 to 60 minutes to deliver the same amount because they apply water more slowly.

Misting nozzles take the cake for the least efficient sprinkler head, Chouinard says. They can use about twice as much water as a rotor head to cover the same area as much of the output is lost to evaporation before the water even hits the ground.

Tip

Chouinard says the best way to determine your sprinkler’s output is to conduct a catch-can test. Simply place a shallow can or container in the grass under your sprinkler and time how long it takes for the water to reach half an inch deep in the can.

So, which sprinkler head is the most water-efficient? Chouinard says low-precipitation rotary nozzles, such as MP Rotators, are the clear winners.

“They need the longest sessions, frequently 45 to 90 minutes, but the slower rate allows better absorption with less waste,” he says.

These estimates are great starting points, but there are also environmental factors to keep in mind.

Yard Features Affecting Sprinkler Run Time

No two yards are identical. Between factors like temperature, soil type, time of year, grass species, and more, there are many factors that affect the ideal amount of water your lawn gets that are left up to nature. Here’s how your lawn watering might vary.

Time of Year

According to Justin Wilson, team leader at American Irrigation Repair, the time of year makes a difference in how long (if at all) you’ll want to run your sprinkler.

Hot, dry summers naturally require more water than cooler, rainier spring or fall days. In warmer climates (like Texas, where Wilson is based), he says that winter watering may be necessary, while in cooler regions, irrigation systems can be fully shut off from mid-October to April. 

Time of Day

Watering your lawn at the right time of day is critical to the health of your landscape, and luckily, there’s no debate about the time of day you should water.

“Early morning is ideal,” David McCary, owner of Seattle Sustainable Landscapes, says, adding that 4:30 to 5:30 a.m. is best.

“This avoids the midday heat, when most of the water evaporates, and there is a greater risk of leaf damage,” he says.

Sun vs. Shade

The light exposure in your yard will also affect how often and for how long you should run your sprinklers. Wilson says sunny areas often need twice as much water as shaded areas.

Soil Type

Similarly, the soil type in your landscape can affect how much water it needs. Sandy, rocky soils, for example, are prone to drying out faster than clay and loam soils.

However, clay soils are also notorious for not absorbing water quickly, so McCary says that homeowners with clay soils should use what’s called the ‘cycle and soak’ method that waters different zones of a yard for different amount of times.

“Instead of running your sprinklers for 30 minutes, you break that into 3- to 5-minute intervals per zone,” he explains. “For sandy soils, you have a bit more freedom to run them for longer because it will penetrate deeper and you can encourage root depth.”

Lawns vs. Garden Beds

Lastly, experts agree that sprinkler run times will vary depending on the area of your yard you’re watering. All things considered, lawns generally follow the same guidelines whether they are in the front, back, or side of your yard.

However, garden beds should be treated differently. In fact, you should avoid using traditional sprinklers on your garden beds all together. 

“Ideally, use drip irrigation or soaker hoses to deliver water slowly and directly to the roots without wetting leaves,” Chouinard says. 

Again, the ideal amount of time to run a soaker hose in your garden depends on several factors, including your soil type, plant needs, and time of year. 

Consequences of Running Sprinklers for Too Long

Of course, water flooding out of your lawn and onto the sidewalk, road, or driveway isn’t ideal, but a soggy lawn isn’t the only consequence of setting and forgetting your sprinkler.

Chouinard says overwatering can invite disease and fungus, lead to shallow roots, cause soil erosion, and leach important nutrients below the root zone, where plants cannot reach them. Altogether, this can result in grass that chronically yellows or turns brown and is far more vulnerable to heat, drought, and foot traffic.

The icing on the cake? The sticker shock you’ll get from your water bill, with only sad, unhealthy grass to show for it. 

“The good news is that these issues are easy to avoid,” Chouinard says. “Stick to deeper, less frequent watering based on what your catch can test shows for each zone. A little observation and smart timing will keep your landscape strong and attractive all season long.”

Read the original article on The Spruce