How to Mow Down Pollution
The environmental impact of millions of Americans cutting their lawns every week with gas-powered machines is enormous, but homeowners can take steps to help curtail their emissions
BY NOW, IF YOU’RE like most homeowners who have lawns, you’ve already hauled out your mower several times this summer. And if that mower happens to be gasoline-powered, you’ve also been spewing excessive amounts of pollution into the environment. “One mower used weekly during the growing season pollutes as much as 43 late-model cars driven 12,000 miles a year,” says Sam Atwood, spokesperson for the South Coast Air Quality Management District, the smog control agency for four urban counties in Southern California. “They’re little pollution factories on wheels.”
According to the U.S. Environmental Protection Agency (EPA), approximately 54 million Americans use gas mowers to cut their lawns. The cumulative impact of so many people maintaining their grass with these machines is staggering. Along with leaf blowers, weed whackers and other gas-powered garden equipment, mowers cause nearly 5 percent of the nation’s air pollution during the summer months.
Though the EPA has proposed new emission standards for the small engines on these machines, at this writing, manufacturers were not yet required to install catalytic converters, the devices that treat motor vehicle exhaust and reduce pollution. Gas lawn mowers churn out high levels of carbon monoxide, an odorless gas. They also produce hydrocarbons and nitrogen oxides, which combine in the presence of heat and sunlight to form ground-level ozone, a key ingredient in the smog that impairs lung function in humans and contributes to other respiratory and heart problems.
Atwood’s agency, like a number of others across the country, runs a program that is trying to wean people away from their traditional mowers. In California’s Orange County and parts of Riverside, Los Angeles and San Bernardino Counties, residents who bring in $100 and their old equipment receive a new electric mower. “We exchange 4,000 lawn mowers a year,” says Atwood. “This is reducing air pollution in our area by 20 tons annually.”
Electric mowers have been around for some time but earlier versions often were impractical because they were tethered to an extension cord. Now, several companies sell cordless mowers that run on rechargeable batteries. They’re quiet and do not require oil changes or spark plugs, says Steve Gladstone, product manager for the Neuton Mower, manufactured in Vergennes, Vermont. “The only limitation is battery time,” he says, noting that a fully charged battery will run a mower for 45 minutes to an hour. “They work best on small to medium-sized lawns.”
Push mowers are, of course, the best choice, especially if you have a small area to cut. But if switching to a different type of mower is not an option, there are still some steps you can take to help reduce your backyard emissions. Here are some possibilities:
Shrink your lawn: Installing a rock garden, for example, will decrease the amount of turf in your yard, making your lawn easier to maintain. Another strategy is to incorporate islands of small native trees and shrubs into the lawn. You can also transform a section of your yard into a native wildflower meadow. By doing so, you’ll be creating habitat for wildlife—something a lawn doesn’t provide. A meadow requires no watering after its young plants are established. It needs mowing only once a year (in late winter, after birds and mammals have taken full advantage of the cover and food it provides). Ask your local native plant society which native wildflowers will thrive in your area.
Use ground covers: Many yards have places where it is shady and difficult to grow grass, or where it is inconvenient or even dangerous to mow, such as a steep slope or incline. Native ground covers—low-growing native plants that seldom or never need to be cut—are good alternatives. Several varieties remain evergreen year-round in many areas of the country. In her book Gardening with Native Plants of the South, Sally Wasowski lists a number of selections for ground covers such as partridgeberry. Green and gold is another good option. In other parts of the country, check with local nurseries to find out what species work best for your region. Wasowski also suggests another idea for the heavily shaded areas of your yard: Grow a carpet of mosses, which resemble a lawn but never need to be mowed.
Use native grasses: Replacing the traditional lawn in your backyard or side yard with a native bunch grass, such as poverty oak grass, buffalo grass or junegrass, is another option. Bunch grasses grow in clumps, not an unbroken stand of green, so they are more informal looking. But they do not require pesticides or fertilizers to flourish and only need to be cut intermittently.
Reducing the size of your turf with an appropriate mixture of all of the above options is an effective way to provide good habitat and attract wildlife. Be sure, however, to check with a local nursery or other horticultural expert to find out which species are native to the area where you live so you don’t introduce new plants that could become invasive in your region.
South Carolina journalist Doreen Cubie wrote about conservation efforts by Minnesota’s Red Lake Band of the Chippewa in the June/July 2007 issue of National Wildlife.
Find out how you can turn your garden into a Certified Wildlife Habitat.