Master gardener says mulching lawn mowers promote grass health

Mulching mowers promote grass health.
Mulching mowers promote grass health.
Many suburbanites would never dream of leaving grass clippings on their lawn after mowing, but a master gardener says a healthy lawn can benefit from natural compost.

A quality mulching lawn mower is designed to leave behind finely shredded grass clippings that won't suffocate the underlying lawn.

But some people fear that leaving clippings on the lawn promotes the formation of thatch - a layer of un-decomposed grass plants that choke new growth.

Have no fear of thatch coming from your new or even used lawn mower, says master gardener Tom Bruton on

"If the lawn is properly mowed, leaf clippings decompose readily and do not contribute to thatch," Bruton writes in response to a reader question.

Mulching mowers have a special blade that chops up the grass more finely before releasing it onto the ground.

The smaller pieces of grass promote faster decomposition to allow the nutrients to reach the soil faster. Because of the nitrogen, phosphorus and potassium in grass, the left-over lawn clippings can provide up to 25 percent of the fertilizer your lawn needs, Bruton says.

As for thatch, it's caused by overfertilizing, overwatering and infrequent mowing, he says.