Mulching Lawn Mowers vs. Grass-Collecting Lawn Mowers


Mowing is one of the essential maintenance practices for any lawn. Properly mowing increases turf thickness and encourage deep root growth. A common question is what to do with all those grass clippings. Mowing companies have developed two answers: the grass-catching lawn mower and the mower that mulches grass as it cuts.

Grass Clippings

Grass clippings are mainly made of water, meaning they disintegrate quickly. Returning grass clipping to the yard provides 25 percent of your lawn's annual fertilizer needs. Clippings are four percent nitrogen, two percent potassium and one percent phosphorous, according to the University of Missouri. Returning grass in one way or another is beneficial.


Mowers with grass catchers collect grass in a bag which can later be disposed of. Grass may be bagged and thrown into the trash or yard waste receptacle, or the grass can be composted. Compost is broken down organic material that creates a fine humus suitable for gardening. Grass clippings break down quickly and provide a lot of nitrogen to the compost pile. Composting takes three to four months, making it a long-term solution. Grass-collecting mowers are excellent tools during times when clippings require removal, such as when your turf is diseased.


Mulching mowers create a fine mist of grass that is blown out of the side of the lawn mower into neat piles. These fine clipping disintegrate quickly, returning to the soil as nutrients. Regular mowing with a sharp blade does not contribute to thatch collecting on the soil surface.


Mulching mowers return grass back to the lawn immediately, improving the nitrogen levels in the lawn. According to the University of Missouri Extension, this contributes little to thatch in the lawn. Mulching mowers may not be effective in returning grass nutrients to the lawn if the thatch layer is greater than 1/2-inch thick. Grass-catching mowers reduce the amount of grass returned to the lawn. This robs the turf of natural sources of nitrogen and increases the amount of chemical fertilizer needed to feed the lawn. Collected grass clippings can be composted, but this takes several months and is best used in the garden, not the turf. Do not use a grass-catching lawn mower if you do not have a suitable area for compost. Each mower has their benefits and disadvantages. Choose a mulching mower if you wish to return grass clippings to the lawn, and a grass-catching mower if you wish to make mulch.

When to Mow

During the spring and the fall, mowing is only required once a week. Cutting more than once a week will reduce the strength of the turf. During the vigorous growing months for your specific variety, mowing is often necessary two times a week.

Keywords: lawn mower types, Grass catching mower, Grass clippings, mulching grass, yard waste

About this Author

Cleveland Van Cecil is a freelancer writer specializing in technology. He has been a freelance writer for three years and has published extensively on, writing articles on subjects as diverse as boat motors and hydroponic gardening. Van Cecil has a Bachelor of Arts in liberal arts from Baldwin-Wallace College.