Conventional Versus Mulching Mowers
Conventional lawn mowers cut the grass just once with a spinning horizontally mounted blade. The grass clippings are then usually sucked out of the mower and spit out the side or back of the lawnmower, usually into a bag. Mulching lawnmowers are a bit different. A mulching mower will cut the grass into very small pieces and leave those pieces on the ground.
Some mulching mowers have two blades inside. The grass is first cut by the main blade, then recut by a second blade above it. Other mulching mowers use specially designed main blades that keep the same grass clippings rotating around under the deck as they are sliced and sliced again. Eventually, the grass clippings become so small and light that they can't be sliced anymore, and settle down into the lawn.
Advantages of Mulching Mowers
Mulching mowers cut down on the cost and waste of keeping a lawn in good shape in a few different ways. When you cut your grass clippings and ship them off to a landfill or put them in a compost bin, all the organic material in that grass is wasted. This means you will have to fertilize your lawn frequently to make up for all that lost green matter. When you mulch your lawn, however, the clippings are redeposited on the lawn. Your mulching lawn mower will reduce your fertilizer use by 25-40 percent, according to the Benton Clean Air Authority. Mulching mowers also reduce water usage by adding a thin, protective layer of organic material on top of the soil. This material stops water from evaporating as readily from the soil, cutting your water bill and protecting your lawn. Finally, mulching lawn mowers are good for the environment. Using one eliminates the fuel cost of shipping clippings off to the landfill or city composting center, and it stops people from wasting clippings that might otherwise end up in the dump instead of a compost pile.