Water your lawn less and reap the eco-benefits

Chicago Tribune (MCT) - Earth Day (coming April 22) has us thinking green, and one of the best ways to go green at home is to use less water in your yard and garden.

April brings showers. Showers revive grass. Soon thereafter, people start showering their lawns.

Yet the average lawn rarely needs to be watered, said Bruce Augustin, chief agronomist for Scotts Miracle-Gro Co., a garden products company.

Many homeowners think they have to water their lawns because everybody does it, Augustin said. Yet federal research shows only about 15 percent of homeowners actually do, and the other 85 percent still have lawns. Here's why _ even if you and your grass are completely hooked on the sprinkler _ you can (and should) start weaning your lawn.

For example, the Chicago area gets about 36 inches of rain a year on average; its grasses need about 43, Augustin said.

Overwatering is bad for your grass. It encourages weak, stunted roots that can't keep the grass alive when the weather gets dry. It fosters fungus diseases and provides a perfect home for root-munching grubs.

Too much watering also pushes grass to grow faster. Lay off the sprinkler and you can mow less often.

What happens to water that your grass doesn't need and can't soak up? It runs off into storm drains and, combined with sewage, increases the load on treatment plants. If you're also overfertilizing, as many people do, the runoff can carry nitrogen and phosphorus that pollute rivers and lakes.

There are other environmental costs. The water from your outdoor faucet had to be taken from Lake Michigan or a well; filtered; treated with chemicals to make it safe enough to drink and pumped to your house, at a cost in energy as well as tax dollars. Using potable water for lawns is wasteful, and "your lawn doesn't really need fluoride," said Debra Shore, commissioner of the Metropolitan Water Reclamation District of Greater Chicago.

In a world in which fresh water is growing ever more scarce, those of us blessed with an abundance of it "have a moral obligation to show that we are using it wisely and carefully and respectfully," Shore said.

Let's start with the lawn. A little awareness goes a long way.

MOW IT HIGH

It's the single most powerful thing you can do to get a lawn that uses less water, has fewer weeds and needs less fertilizer: Set your mower as high as it will go and leave it there.

Short grass is weak and needy. Taller grass _ 3 to 4 inches _ grows deep roots that absorb water and nutrients efficiently, collects more life-giving sunlight and shades or crowds out many weeds. No, you won't have to mow more often. But when you do, leave the clippings on the lawn to return moisture and nutrients to the grass.

GET A RAIN GAUGE

Knowing how much rain has fallen will reassure you that you don't need to water.

CHECK

When tempted to water, get a trowel and dig out a plug of lawn. If soil is moist within the plants' root zone, 3 or 4 inches down, leave the sprinkler in the garage.

GET STURDY GRASS

Fescues are tough and thrifty with water. Usually fescue seed is mixed with bluegrass, which is less drought-resistant but finer and spreads to knit the lawn together. Use a fescue-rich mix to seed or overseed. If your lawn is all bluegrass, overseed yearly with fescue.

ESTABLISH GRASS WELL

The only time to water every day is when you have scattered seed, in early spring or early fall, and are waiting for it to sprout. A brief sprinkle will do, just enough to keep the seed moist. Spread mulch to hold the water around the seed. Scotts has a couple of new products designed to help: EZ Seed, which mixes seed, starter fertilizer and recycled coconut-fiber mulch for easy patching; and grass seed with Water Smart, a moisture-retaining coating.

EMBRACE SUMMER DORMANCY

Grass naturally quits growing and dries out in the hottest part of summer, then revives and greens up when fall rains come. Go with the flow rather than watering to force the grass to stay all-green, and you'll save water and escape mowing under the hot August sun. Fescue browns less than bluegrass.

WATER LONG AND DEEP

When you do water, run the sprinkler long enough to lay down the equivalent of 1 inch of rain. (Use a rain gauge or a tuna can to check.) Don't water again until your trowel test tells you the grass needs it.

FERTILIZE, BUT NOT TOO MUCH

A good lawn does not require the heavily advertised five-times-a-year fertilizing schedule. An application of slow-release fertilizer once in spring and once in early fall is enough. Organic fertilizers are now widely available.

AND WORK ON THE SOIL

Top-dress with screened compost at least once a year to foster the rich ecosystem of underground organisms that delivers nutrients to roots and makes soil great.

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© 2009, Chicago Tribune.