How large a lawn do you need to mow?
If your lawn is smaller, the size of most "in-town" lots, and/or if your lot is flat, perhaps you can consider mowing it with a reel mower powered by yourself! This is the most eco-friendly option and, if maintained properly with the blades kept sharp, this option can produce a very clean cut.
If your lawn is too large or rolling to cut conveniently with a reel mower, why not consider a corded or rechargeable battery operated electric lawn mower? They are much cleaner (for the environment) and quieter than a gas powered mower and require less money for maintenance.
For lots where corded or cordless lawnmowers will not suffice, consider using a four-stroke gasoline engine with Electronic Fuel Injection (EFI). These lawnmowers emit less pollutants and will work longer on an equivalent amount of fuel when compared to two-stroke and non EFI four-stroke gasoline powered lawnmowers. Proper maintenance (replacing the spark plug/changing the oil/keeping the blades sharp, removing build-up) will help improve efficiency and reduce pollutants.
For acreage, consider Diesel powered ride-on mowers, an option that is more efficient than gasoline. Another less popular, at the moment, but far cleaner option is a propane powered ride-on mower.
And there are solar powered and electric robotic mowers, but they are still very expensive, perhaps in time they too, become a pragmatic option.
If your lawn is beyond repair, consider other more environmentally friendly lawn alternatives. Ideal seeding times are the fall and spring.
Chris Smith CSSBB
Chay Realty Inc., Brokerage