Many traditional lawn mowers can be converted into mulching mowers with the addition of a special cutting blade or kit. The term "mulching" refers to a process by which cut grass is whittled down in size even more and allowed to fall to the ground, rather than being bagged and removed. The purpose is to provide moisture and nutrients to the lawn. By this process, a mulching mower is estimated to provide a healthier lawn for home owners. If you're not sure whether or not your present lawn mower mulches, contact your local dealer or the manufacturer, or simply look beneath it.
Mulching is not a complicated process. It is achieved by installing a smaller blade, called a mulching blade, above the main cutting blade. Air flow causes the grass cuttings to be lifted up into the mulching blade, where they are cut repeatedly into successively smaller pieces until eventually falling to the lawn. By this time, the cuttings are so small as to be almost undetectable. A simple visual inspection of the underside of your lawn mower can reveal whether or not a mulching blade is installed.
For some mowers, more advanced mulching kits are available that go beyond the simple addition of a mulching blade, especially when it comes to riding lawn mowers. A riding mower provides the option of attaching skirting and baffles that keep the cut grass recirculating for a longer period of time, resulting in a finer mulch. More involved kits like this sometimes cause a noticeable loss of power to the lawn mower and also can run into clearance problems with the regular cutting blades.
Grass isn't the only material perfect for a mulching mower. Fall is the time you see many people out mowing leaves. This is not just an odd hobby. Mulched leaves provide the same type of moisture and nutrients for the fall season as grass does during the summer. The same goes for small leaves. All this bio matter is easier to chop and disperse on the fly with a mulching mower, as opposed to alternatives like a chipper, which sits in one place and requires hand dispersal.
The bottom line is that the main difference between a mulching mower and a lawn mower is the fineness of the cut achieved. Where a traditional lawn mower is intended to cut the lawn down to a nice even appearance, adding mulch capability is intended to keep your grass healthy by returning nutrients to it. If you're interested in a mulching power, you can certainly find models pre-fitted with the capability from the factory.