Recycle, don’t bag, clippings
Published 4:30 pm Tuesday, April 14, 2009
Question: We laid new zoysia sod last year and want to do the right things to make it look good and stay healthy. The question we have is about what to do with the clippings when we mow. Some say bag them, some say use a mulching mower and let the clippings decompose naturally. What do you say?
Response: I say if at all possible, recycle your clippings. Grass clippings are a resource of valuable plant nutrients and organic matter for your soil. If you leave your clippings on the lawn, they will decompose and improve the growing conditions in your turf. During the break down process, the clippings feed soil organisms, recycle plant nutrients and contribute organic matter to the soil. This results in water conservation and not having to fertilize as often.
Fresh grass clippings contain about 4 percent nitrogen (N), 0.5 percent phosphorus (P), 2 percent potassium (K), and small amounts of other needed nutrients. As much as 50 percent of the N that you apply as fertilizer is removed when you collect your clippings.
Research from several universities has shown that clippings can supply up to 25 percent of the lawn’s total fertilizer needs. One study found that the N from grass clippings began showing up in the growing grass within 2 weeks. By the end of the third year of the study, researchers estimated that about 1/3 of the N found in the existing grass came from previously recycled clippings.
When bagged, clippings simply become waste and are put in a landfill. When they decompose in our landfills, the nutrients they contain are not only wasted, but they also contribute to landfill leachate and ground water contamination. Believe it or not, grass clippings typically comprise 10 – 20 percent of the solid waste collected by communities on a year-round basis. During the summer months, grass clippings can account for nearly half of the waste collected in some communities.
The height of your lawn greatly influences the performance of your turf. How high and how often you mow your lawn will depend on the grass species. As a general rule, you should mow often enough to take off no more than 1/3 of the length of the grass blade per mowing. While this may cause you to mow more often (every five days rather than seven), you will more than make up your extra mowing time by not taking the time to bag. It has been shown that it takes 30-38 percent less overall time if you don’t bag your clippings.
Hopefully this helps you with your decision. By not bagging your clippings, you help your grass and your environment, and you even save time and money. Sounds like a no-brainer to me. Good luck!