Why You Need a Mulching Lawn Mower

Mulching lawn mowers mash up clippings into small particles that nourish your grass. They're great for the lawn and the environment.

Our editors and experts handpick every product we feature. We may earn a commission from your purchases.

Mowing a lawn is enough of a chore without going back and raking up the clippings. But if you don’t do it, that bed of clippings might suffocate the grass.

You could collect the clippings in a bag, dump them in a pile, add in other organic material and turn it into useful compost. Or you could pulverize the clippings into particles small enough to safely leave on the lawn. That’s exactly what a mulching lawn mower does.

Mulching lawn mowers come in all power options, including gas and electric (corded or cordless). Some you ride, and some you push. If you like your current lawn mower, there may be a kit that lets you convert it to a mulching model. No matter which kind you choose, you’ll have greener grass, because the mulch adds nutrients to the soil.

How Does a Mulching Mower Work?

Mulching mowers feature rotary blades that spin on a horizontal plane. But instead of the straight blades, like a conventional rotary lawnmower, these are shaped to direct clippings toward the underside of the deck and cut them several more times before falling back on the lawn. Some mulching blades are curved, some serrated, and some are both.

A mulching mower has no side or back outlet. This allows clippings to swirl around under the mower deck. When you buy a conversion kit, it typically includes a cover for the discharge opening. The mower won’t mulch properly without it.

How To Use a Mulching Mower

If you’re not careful, some of that swirling grass under the deck of a mulching mower may band together into clumps, which the grass can’t absorb. Here’s how to prevent this:

  • Mow the grass only when it’s dry. Wait for the morning dew to dissipate. If you’re planning to water, do it after you mow.
  • Mow the grass often. This prevents oversized clippings from creating a layer of thatch.
  • Mow more slowly than you would with a regular mower to give the blades times to mulch.
  • Clean the blades and the underside of the deck before and after mowing.
  • Sharpen the blades frequently to maintain cutting power.
  • Weed the lawn before mulching. If you mulch weeds, you just spread the seeds. If the lawn has lots of weeds, bag the clippings until you can reduce the weed population.

To keep the grass healthy, set the mower height so that it cuts no more than one-third of the length of each blade. The grass should generally be about 1/2-in. longer than it would be if you were collecting the clippings. This keeps the roots healthy and hides the pulverized clippings that fall back onto the lawn.

Is Mulching Good for Your Grass?

Yes. And it’s also good for the environment.

  • Clippings provide nutrients the grass needs, including nitrogen, potassium and phosphorous. Because the clippings are ground into small particles, they decompose quickly, making the nutrients readily available.
  • Waste products from the microorganisms responsible for decomposition combine with the soil to produce carbon-rich humus. This helps the soil retain moisture. A cover of fresh clippings aids that process.
  • According to the Environmental Protection Agency, yard trimmings account for more than 12 percent of municipal solid waste. So every bag of clippings used as mulch takes some strain off your local landfill.

Top Mulching Lawn Mowers

If you’re looking for a push mower, you can choose a corded, cordless or gas model. Or you could opt for a gas-powered riding mower. Here are some awesome mid-range choices. Once you’ve finalised your pick, don’t forget about getting a lawn mower cover, too.

Best Corded

 Greenworks 12 Amp 20' Corded Lawn Mowervia merchant

The GreenWorks 12-Amp Corded Lawn Mower offers back or side discharge as well as mulch mode. There are no emissions and no batteries to charge.

Best Cordless

Worx Wg743 40v Power Share 4.0ah 17' Cordless Lawn Mowervia merchant

The Worx 40V Power Share comes with a battery charger and two 20V batteries that provide enough power to mulch 1/8-acre on a single charge. The batteries can be used with any other Worx tools.

Best Gas

 Craftsman M105 140cc 21 Inch 3 In 1 Gas Powered Push Lawn Mower With Baggervia merchant

The Craftsman Gas Powered Push Lawn Mower is a standard pull-start mower with auto-choke, which means you simply pull the cord and go. Like the GreenWorks, it offers back and side discharge plus mulching options. It features six height settings and a 21-inch cutting deck.

Best Riding

 Husqvarna 42' 18.5 Hp Hydrostatic Riding Mower via merchant

The Husqvarna Riding Mower offers an 18.5-horsepower gas engine and a top speed of 7.4 mph, making it one of the faster riding mowers on the market. Air induction prevents grass from flattening under the blade. The mulching kit and clipping bag are sold separately.

Chris Deziel
Chris Deziel has been building and designing homes, and writing about the process, for over four decades. He developed his construction and landscaping skills in the 1980s while helping build a small city in the Oregon desert from the ground up. He's worked as a flooring installer, landscape builder and residential remodeler. Since turning his focus to writing, he has published or consulted on more than 10,000 articles and served as online building consultant for ProReferral.com as well as an expert reviewer for Hunker.com. Though his specialties are carpentry, cabinetry and furniture refinishing, Chris is known by his Family Handyman editors as a DIY writer with a seemingly endless well of hands-on experience.