Once a week, my town sends an 18-ton sanitation truck rumbling down my road to collect yard waste. As the crew gathers up bag after bag of lawn clippings from my neighbors, I can’t help feeling that robbery is afoot. But far more is at stake with a lawn than what happens when grass clippings are trucked away instead of being left to return their rich nutrients to the soil.
Lawns are a 20th-century import from northern Europe. Most lawn grasses are better suited to English gardens than to the varied soils and climates in our North American yards. So maintaining a traditional “putting green” lawn often requires extreme measures that have profound effects on your yard’s ecosystem. Consequently, they’ve been called “green deserts.”
According to the U.S. Environmental Protection Agency, American lawns guzzle up to 60 percent of our cities’ clean water annually, plus 67 million pounds of pesticides and $5 billion in fertilizers (more fertilizer per acre than farmers use). Conventional lawns account for an estimated 90 percent of landscaping costs. In addition, 10 percent of the air pollution caused by gasoline engines comes from lawn-care equipment.
Overuse of pesticides, weed killers, and chemical fertilizers destroys the soil’s natural ecology by eradicating most earthworms, insects, spiders, and millions of other beneficial organisms necessary for your garden’s health. Surviving pests can develop resistance to chemicals, leaving lawns dependent on even stronger chemicals. In addition, the shallow, dense root systems of lawn grass prevent moisture from penetrating deeply into the soil, causing run-off of precious rainwater.
To birds, frogs, bees, and other wildlife, a conventional lawn has all the appeal of a sun-blasted concrete parking lot. As with concrete, a large expanse of clipped lawn reflects more heat than do natural plantings, resulting in higher summer cooling costs for nearby houses.
Lawns do have their uses, and it’s understandable that most people aren’t willing to give them up completely. Still, many gardeners have decided to replace their lawns (or parts of their lawns) with more natural, earth-friendly plantings. Shrinking or eliminating a lawn can be a formidable undertaking, so it’s best to tackle the conversion in stages over several years.
Develop an overall plan. Decide how much lawn you really need, and for what purposes. A landscape designer can be helpful. Local nurseries and your county extension agent can offer advice on replacement plants suitable for your soil and climate. Besides trees, shrubs, ground covers, and nonlawn grasses, your master plan might include vegetable gardens, mulched walkways, bird-feeding stations, and ponds.
Phase in the changes. Set up a season-by-season schedule for your lawn conversion, arranged in order of importance. Shade trees should get high priority, since they require years to mature. And if you’re replacing lawn grass with drought-tolerant native plants, put them in areas farthest from water outlets—this will substantially reduce watering chores as soon as the new plants become established.
Kill unwanted grass. Using herbicides to eradicate grass can harm beneficial soil organisms. Instead, I’ve had good results using two or three layers of newspaper covered with grass clippings, shredded leaves, or wood chips. This starves grass of light while allowing rainwater to penetrate the soil. In small areas, you can simply dig out lawn grass by hand.
Tips for Growing Non-Toxic Lawns:
If you still want to grow some grass, you can minimize your use of chemicals and water
by following these tips:
• Mow with a sharp blade. Dull blades tear the grass, providing openings for disease organisms.
• Cut only one third of the grass blade at each mowing. Taller grass suppresses weeds and develops deep, drought-tolerant root systems.
• Leave grass clippings on the lawn. They supply at least a third of your lawn’s yearly nitrogen requirement.
• Water deeply and infrequently. Frequent, light watering encourages shallow roots and reduces drought tolerance. To reduce evaporation, water in the early morning.
Sandra Dark is a garden and science writer based in Norman, Oklahoma.