Are You Over-Watering Your Lawn?

West Harris County Regional Water Authority

Just because you have an irrigation system doesn’t mean you’re saving water…

How often does your irrigation system come on when your grass doesn’t need any water? Have you been putting off checking the system? Perhaps you rationalize that it isn’t hurting the grass, so what’s the harm? Actually, besides the obvious answer that it is wasting water and money, too much water DOES harm your lawn. Overwatering encourages turf to grow shallow roots which cause the grass to stress if water isn’t available. And, if your system is still on during the winter months when St Augustine and other native grasses are DORMANT and need no more water than Mother Nature provides, the waste factor multiplies.

Experts point out that the basic recipe for growing healthy grass while saving water is tied to selecting the right grass for the location, having really good soil, and understanding exactly how to take care of it. That means knowing specifically how much water it really needs to thrive.

About half of the lawns in Texas are planted with St. Augustine grass, which many believe is especially “thirsty”. According to the experts at Texas A&M AgriLife Extension, however, that might be a “bad rap” since all grasses use about the same amount of water at the same rate when it is available in the soil. The ability of a turfgrass to survive if water is restricted depends on its drought tolerance and the type of soil — how deep it is, and how appropriate it is for growing the type of grass that is planted. The deeper the soil, the more likely the grass can survive even 60 days without water.

Throw out the old “inch of water a week” advice that may or may not be the formula for your lawn. Most yards can get by with less than half of the irrigation currently applied. Water moves into clay soils at a rate of about 0.09 inches per hour…not very fast. An irrigation system, on the other hand, may apply water at a rate of 0.25 to 1.5 inches per hour or more. Delivering water faster than a soil can absorb during one application results in water moving across the soil surface, running into the gutter, and down into the storm drain – and that causes another problem altogether.

Stop training your grass to be a water hog!

Start by accepting the fact that “lawns don’t waste water, people do!” If you water your yard only when it needs it, for example, you could save between 750 and 1,500 gallons of water a month. Encourage the grass to grow deeper roots by watering it sparingly. Here are some common sense suggestions to help you implement a realistic, cost-effective irrigation efficiency plan:

  • Use native plants and shrubs whenever possible in landscaping your yard. They tend to be more drought-tolerant, require watering less frequently, and are often low maintenance, too.
  • Different varieties of grasses, plants and soils use different amounts of water. Experts suggest that grass be watered separately from flower beds and landscaped areas so, whenever possible, “zone” plants according to their water requirements.
  • Set the system controller to complete the watering cycle before 4:00 a.m. to avoid peak demand for household water use, and avoid the excessive evaporation that occurs in strong sunlight.
  • Set the controller for “Cycle and Soak”.This method applies water slowly so the soil can actually absorb it. Each lawn has different components – soil quality and content – but the key here is to water only as long as it takes to get moisture down into the soil, and that could be as little as 10 minutes or as many as 20 depending on the soil. It will take at least 30 minutes for the water to percolate into the soil, so wait an hour to schedule the next cycle. Do a test run; turn on a zone to discover at what length of time water is no longer soaking into the soil and begins to run off. Use that amount of time to set the first “cycle.”
  • Set the timer to come on again after an hour, to deliver a similar amount of water. Technically, while you may be watering more often, the system is delivering the same amount of water…only it is being utilized more efficiently!
  • Avoid cutting the grass too short. Longer blades of grass will reduce evaporation and root stress since shaded soil will not dry out as quickly. Raising the lawn mower blades just one notch higher can save between 500 and 1,500 gallons a month.
  • Apply fertilizer sparingly to develop the root system and to help keep the lawn healthy. Too much fertilizer, however, will lead to excessive growth…which will then require more watering. Many experts recommend leaving the grass clippings on the lawn, which will minimize the need for additional fertilizer.
  • Stormwater runoff can carry fertilizer directly to streams and rivers, where it can seriously harm water quality. Take care to keep any fertilizer you use on the grass and not on concrete driveways or streets.
  • Use a sprinkler that emits large drops of water that remain close to the ground instead of one that sprays a fine mist into the air. Don’t water on windy days; this can waste up to 300 gallons in just one watering!Also set the sprinkler so that the lawn is watered…not sidewalks and driveways.
  • If you have a sprinkler system, add a rain sensor that will not allow the system to come on if Mother Nature has already watered the lawn for you.
  • For any small areas of grass, consider using a hose to water by hand to keep waste to a minimum.
  • Use plenty of mulch in the landscaped areas. Not only does this provide a nice, “manicured” look, but the mulch helps keep the ground from overheating, holds moisture that would otherwise evaporate, and helps to discourage weed growth. A good mulch layer can save up to 1,500 gallons of water a month.
  • Use the kind of watering equipment to suit your “target.” Use sprinklers for the lawn areas, and soaker hoses or drip irrigation systems for trees, shrubs, and flower beds.
  • Use drip or trickle irrigation — the slow, frequent application of small amounts of water to the soil area directly surrounding the plant roots — to take care of container plants, small gardens, and landscaped areas. Drip irrigation can save up to 60 percent of the water delivered by other systems.

The article above was originally published in the June 2020 Edition of the WHCRWA WATERWORKS Newsletter.

WHCRWA Waterworks June 2020 Newsletter

WHCRWA Waterworks June 2020 Newsletter (Spanish)

Share This Story, Choose Your Platform!

Published On: June 17th, 2020Categories: Irrigation

Latest Updates