Here’s Why You Need to Leave Grass Clippings On The Lawn

Updated: Aug. 14, 2023

Gathering up those grass clippings has always been an integral part of the lawn care routine. But after looking at the science, it may not have to be a part of it after all.


It’s every homeowner’s dream to have a healthy lawn, and cleaning the lawn after mowing feels like second nature. You grab that brown paper bag, some sturdy work gloves, and clean up all of the clippings on the lawn. Sure a few here and there won’t hurt, but if you leave too much, it could cause some serious thatch problems in the soil. Right?

Actually, that’s false! According to a few scientists who have studied turf grass and agronomy, it seems that grass clippings won’t affect (or create) thatch like you previously believed. Turns out, grass clippings can actually help with the overall health of your lawn.

First, let’s look what thatch is. If you aren’t familiar, thatch is a layer of plant material that has built up over time. It’s located between the grass and the roots of the grass plants. It develops from roots, shoots and leaves that cover the grass and it’s surrounding. Although thatch can help protect the roots of grass, too much thatch can cause problems getting the soil underneath proper moisture, oxygen and nutrients.

Since these other plant materials are causing thatch to build up, it would only make sense that grass clippings would be part of the problem. But according to Professor Peter Landschoot Ph.D. (director of Penn State’s Center for Turfgrass Science) and Aaron Patton Ph.D. (professor of agronomy at Purdue University), it’s not the case. In an interview with EcoMyths, they explain that grass clippings are mostly made of water and have an 80 to 90 percent composition rate. Once the clippings completely dry out, there’s very little biomass. The biomass that remains is actually high in nitrogen and microorganisms, which feeds the grass and gives the soil the nutrients it needs.

Since grass clippings aren’t contributing to the thatch problem and they are helping to naturally water and feed your lawn, it seems that leaving your grass clippings on the lawn would be your best bet.

Is your lawn in need of some serious repair? Here’s how to repair your lawn. And if this thatch/grass clippings issue blew your mind, then you better read up on these other lawn care myths.