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Sprinkler tuneup key to avoid water waste

KENNEWICK -- If I stamp my feet and hold my breath until I turn blue will anyone listen to me when I talk about how to water a lawn?

I wonder.

Every year, for more than 20 years, I've taken a much more adult and professional approach, calmly pointing out that watering your lawn more deeply but less frequently is best.

However, I don't think many people are listening to this repetitive diatribe.

I'm not the only one who is compelled to provide lawn irrigation guidance with the same message.

In the USDA's Natural Resources Conservation Service's lawn irrigation guide points out that "Many homeowners irrigate too often and for too short a period to meet lawn and especially landscaping (tree and shrub) needs. Others tend to leave the water running too long, resulting in wasted water."

They go on to say, "Irrigating less often and applying more water per irrigation results in deeper rooted plants and a healthier turf. Grass roots grow deeper into the soil and the plants become stronger if enough water is applied when you do irrigate." That's what I said ... water deeply less frequently.

The beginning of a new irrigation season is a good time to establish different lawn watering practices, especially because some parts of our region may experience restricted watering this summer.

With the start of the season, check your system. Fix any leaks or heads that don't function properly.

Test your system to determine that it's working right and applying water evenly. You can do this by placing four to six identical, straight sided cans at different distances from the sprinklers in one zone.

Turn that zone on for 20 minutes. Then measure the depth of water in each of the cans and determine the average depth of water being applied in that zone. If the cans vary widely in depth, you need to check those sprinkler heads and adjust them so water is applied evenly throughout the zone.

Repeat in each of your zones. This also tells you how much water you are applying in a set amount of time.

Runoff is wasteful and it indicates a problem. Either your system is putting out water faster than your soil can absorb it or you are trying to water a slope. Whether your runoff is caused by applying water too fast or from watering on a slope, consider watering in cycles.

Set your system so the water is on for five minutes, then off for five minutes. Repeat this pattern until the water soaks into the desired depth.

You also can save water by not watering sidewalks and driveways, another cause of runnoff.

Once your irrigation system is tuned up, you'll want to apply enough water to moisten the soil to a depth of about eight inches, that's the effective rooting depth of most turf grasses.

Several hours after watering, use a trowel to check the depth of the moisture in the soil beneath the grass.

I could tell you complex formulas that might help you scientifically determine when and how much you should irrigate your lawn, but it's much simpler to let the grass tell you.

A Kentucky bluegrass lawn is telling you it needs water when it turns blue-green and your foot steps don't spring back when you walk across the grass.

In essence, the grass is stamping its feet and turning blue telling you it needs water.

* Marianne C. Ophardt is a horticulturist for the Washington State University Benton County Extension Office.

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