Grass clippings make up a surprisingly large portion of California's solid waste stream during the growing season. With few exceptions, it is actually best to leave the clippings on the lawn after mowing. This practice, termed “grasscycling,” is growing in popularity as California communities try to reduce the amount of waste going to landfills.
Grasscycling saves time and money, and helps the environment. Mowing time is reduced since bagging and disposal of clippings is eliminated. Grass clippings add valuable nutrients and organic matter to the soil and produce healthy, green lawns. About 20% of the fertilizer requirements of most grasses can be attained just by leaving the clippings on the lawn. Grasscycling reduces turf grass fertilizer and water requirements, which minimize chemical runoff entering storm drains and polluting creeks, rivers, and lakes.
Grasscycling reduces the amount of yard trimmings disposed in landfills which historically have comprised half of the yard trimmings deposited in California landfills. Research has shown that lawns generate approximately 300-400 pounds of grass clippings per 1,000 square feet annually which equates to as much as eight tons per acre each year.
Grasscycling can be practiced on any healthy lawn as long as the turf is properly managed. Unfortunately, many people treat a lawn as if it were a crop: overwatering and overfertilizing it to encourage maximum growth, and then “harvesting the crop” by bagging the grass clippings and transporting them to a landfill. Successful grasscycling requires proper mowing. With frequent mowing, you will have short clippings that will not cover the grass surface if left on the lawn and will quickly decompose.
There are times, however, when grasscycling is not appropriate. Prolonged wet weather, mower breakdowns, or other circumstances that reduce mowing frequency and thus lead to an excessive volume of clippings probably dictate that the grass clippings should be bagged. But do not throw those clippings away! Grass clippings make an excellent addition to a backyard compost pile. Clippings can also be used as mulch to provide weed control and prevent moisture loss in flower beds and around trees and shrubs. In some situations, however, you should not mulch with clippings: if the clippings are of an invasive species such as bermudagrass or if herbicides were recently applied to the lawn, the clippings can be harmful.
If you have a gardening related question you can contact the UC Master Gardeners at 209-953-6112. More information can be found on our website.
Information was taken from the UC Guide to Healthy Lawns