Match the mower to your lawn :

• Manual-reel and walk-behind electric mowers are fine for small, flat lawns. Neither produces any exhaust.

• Gasoline/Petrol-powered walk-behind mowers are good for lawns of up to half an acre and effective at handling long, thick grass and weeds. However, they emit air-polluting exhaust fumes, are relatively noisy and require regular maintenance.

• Riding mowers and tractors are best suited to large lawns. Tractors are useful if you plan to use attachments to plow (earth) or to tow a cart. Riding mowers and tractors have better emissions controls than walk-behind models but consume more gas per acre. They are also among the most repair-prone products, we have found.

Can you reduce the size of your lawn?

The time and money (about R1500 per acre annually) needed to maintain a lawn has led many homeowners to seek out alternatives, such as replacing a portion of their grass with other types of ground cover or landscaping. A smaller lawn also means fewer emissions from your mower since you’ll be using it less.

Making the right choice

Consider a manual-reel mower for very small lawns. Reel mowers are quiet, inexpensive and nonpolluting. They’re also relatively safe to operate. But, they’re practical only for small flat lawns of about 5,000 square feet or less, and they don’t cut as well as the other types, according to Consumer Reports tests.

For electric mowers, decide between corded and cordless. Keep in mind that corded mowers limit your mowing area to the length of your power cord. Cordless versions, while more versatile, weigh up to 30 pounds more than corded models and can typically mow just one quarter to one third of an acre before their batteries need recharging.

If you buy a gas-powered model, make sure it meets the latest  standards and the more stringent emissions requirements. Regulations have cut smog-forming gasses in recent years and will continue to get more stringent over time. However, a dealer’s inventory could be several years old, so not every model you see for sale may meet the current standards. A label on the mower should indicate the standards it is certified at meeting.

Get a mower that can mulch as it mows. Not only does this decrease the amount of clippings that end up in landfills, it’s more convenient than emptying a bag and also provides natural fertilizer for your lawn.

Buy a no-spill gas can. These cleaner, more environmentally friendly containers can significantly decrease the amount of air-polluting emissions. No-spill gas containers can make filling lawn mowers and other gas-powered equipment a little less messy. Some containers have automatic shutoff valves that stop the fuel flow when the level in the gas tank reaches the tip of the nozzle. With others, you push a button to control the flow rate.

Getting the most value

Mulch as much as possible. Mulching is good for your lawn, your wallet and your local landfill.

Cut your grass higher. By leaving your grass at least 5 cms (2½ inches) high, you can help trap moisture and reduce the amount of watering you’ll need to do.

Maintain your mower:

Keep gas-powered engines tuned: For four-stroke engines, change the oil each mowing season, draining the crankcase and refilling with manufacturer-recommended oil. Replace any spark plugs that have heavy deposits and clean or replace the air filter once each mowing season or as needed. A tuned engine runs more efficiently and releases fewer pollutants.

Clear the deck: To maintain proper airflow and foster better performance, use a plastic trowel to keep the deck clear of clippings (disconnect the spark-plug wire if the clippings are damp).

Sharpen the blade: Sharpening once a season should suffice. It’s fairly easy to do yourself and inexpensive to have done at a repair shop. This is important for your lawn’s health. Dull blades tear grass, leaving a larger area of tissue vulnerable to disease.

Recharge cordless electric models correctly. Draining a battery completely shortens its life. Stop mowing and plug in the charger when the battery starts running down. Manufacturers also suggest leaving the battery on “charge” when you’re not using the mower.

Prepare your gas mower for the off-season. At the end of the mowing season, add a stabilizer to prevent deposits that can clog the fuel passages, then briefly run the engine to circulate the mixture. In most cases, stabilizers eliminate the wasteful and polluting practice of draining the tank at the end of the season.

Why it matters

Gas and electric lawn mowers contribute to air pollution. Whether gas-powered or electric, lawn mowers have a large collective impact. Gas mowers generate emissions directly; electric mowers, indirectly in the form of power-plant emissions. In addition to carbon dioxide, the major climate-changing greenhouse gas, lawn mowers generate other pollutants, such as nitrogen oxides and hydrocarbons, which play a prime role in the formation of low-level ozone, smog, and acid rain.

Gas cans also cause pollution. Besides the obvious problem of gasoline that’s accidentally spilled when filling the mower, gas fumes can permeate the plastic wall of the “can” (about 75 percent of these containers are actually plastic). Evaporation from improperly capped spouts is another problem. The newer, no-spill gasoline containers can help.

Grass clippings pile up in landfills. A 1,000-square-foot lawn can generate about 300 pounds of clippings a year. Multiply that by a typical suburban neighborhood and you can quickly see the impact.

Recycling and Disposal

Weigh repairs against better emissions and efficiency. Like most energy-using products, lawn mowers now burn cleaner, which can help you justify buying a new model instead of repairing an ailing one. However, because mower repairs are fairly inexpensive and emission improvements are incremental, we believe repairs are worth considering for mowers of up to 7 years old. Exception: If the repairs would cost more than half what you’d pay for a new mower, buy the new one.

Recycle lead acid batteries. Electric mowers use sealed, lead acid batteries that should be returned to the retailer or turned in on your local household-hazardous-waste collection day for proper recycling.

Compost what you don’t mulch. If your grass has grown too high to mulch, compost the bagged clippings, so you can eventually use them to feed your lawn or garden.