Winning the turf war

March 1, 2011

12:00 AM

In the never-ending fight to maintain a green, healthy lawn, there is one unavoidable fact: It’s a jungle out there.

We share our yards with a wide assortment of nature’s weeds and insects, and unless you call in the folks at Astroturf, that’s just how it is. But don’t despair. With a few simple tweaks to the lawn-care chores you’re already doing, you can give your turf grass a competitive advantage and enhance its natural ability to ward off invaders.

Three factors make or break a lawn: mowing, fertilizing and watering. As with most things in life, timing and moderation are the keys to success. Here’s how to win your “turf war”—and still have your weekends free.

Just a little off the top

The biggest mistake most homeowners make is letting the grass grow too tall before "scalping” it—mowing it down to the approximate height of a drill sergeant’s crew cut. This stresses the plant and hampers root growth. Each of the common grass varieties in South Carolina has an ideal growing height (see chart), so adjust your mower accordingly.

A good rule of thumb is to remove no more than one-third of the ideal grass height at a time. If you’re trying to maintain tall fescue at a height of 3 inches, for example, you’ll want to mow 1 inch off the top when the grass reaches a height of 4 inches. Keeping grass at the correct height may require you to mow a little more often than you’re used to, but the rewards are worth it. Proper mowing will keep the plants strong and healthy, and you can skip the hassle of bagging and disposing of cuttings. The short clippings can be left on the yard where they act as a natural fertilizer.

One more tip: Before you fire up the mower this season, have the blade sharpened. Sharp blades cut grass cleanly which ensures rapid healing. Dull blades tear and bruise the leaves, making your lawn vulnerable to invading weeds, insects and diseases.

Feed the troops

Proper fertilizing has a direct impact on the health and appearance of your lawn. Cool-season grasses, like the tall fescues found from the Piedmont to the foothills, should be fertilized in the fall. Warm-season grasses, like Bermuda, centipede, St. Augustine and zoysia, which grow from the Piedmont to the coast, are best fertilized in the late spring and early summer, ideally two or three weeks after the lawn has completely greened-up or come out of winter dormancy.

The key nutrients in fertilizer are nitrogen, phosphorus and potassium, but it’s the nitrogen that controls how much fertilizer you need to apply. Don’t overdo it. All you really need is 1 pound of nitrogen per 1,000 square feet, and at least 25 to 50 percent of it should be in a slow-release form. Never over-fertilize. At best, you’ll create an overgrowth situation that is attractive to turf-eating insects. At worst, you’ll just be throwing money away and causing potential harm to the environment in the form of polluted ground and surface water. For more tips on when and how to fertilize your yard, see the pamphlet “Fertilizing Lawns,” (HGIC 1201) available at clemson.edu/extension/hgic

Turn on the water works

Turf grasses, like all living plants, require water for growth and survival. If nature doesn’t provide it, you’ll have to step in.

Early signs of a thirsty, drought-stressed lawn include leaves with a bluish-gray cast, footprints that stay in the grass, and leaves that are wilted and rolled. When you see these conditions, apply a gentle soaking of about three-quarters to 1 inch of water to your lawn. This is equivalent to 465 to 620 gallons of water for each 1,000 square feet of lawn. \

If you have heavy clay soil, you may not be able to apply this much water in one session. If water starts to pool or run off, turn off the sprinkler for half an hour and let the water soak in. Repeat the cycle as needed until you’ve applied the full inch. For fast-draining sandy soils, apply a half-inch of water at a time, about every three days. The best time to water? At night. If you irrigate at midday, in hot, dry and windy weather, 30 percent or more of the water you’re putting on the lawn will simply evaporate. Watering at night cuts evaporation in half and can save a significant amount on your water bill.

Don’t water again until you see the return of drought-stress symptoms. This encourages the deep root growth that supports a healthy lawn. Watering too often only makes grass less drought-tolerant, while encouraging the growth of common weeds. Unless yours is a newly seeded, sodded or sprigged lawn, there is absolutely no need to water every day.

Declare victory

And that’s it. Unless you require the absolute perfection of a PGA putting surface, proper mowing, fertilizing and watering don’t take much more time and effort than you’re already putting into your turf war, only now you’ll have a naturally healthy yard to show for it.