Do clippings returned to the lawn contribute to thatch problems?
Thatch is a layer of undecomposed or partially decomposed grass roots, stems, crowns, runners and lower shoots that accumulate between the soil surface and actively growing turf. Grass clippings contain 80 to 85 percent water and decompose much more quickly than other grass plant parts. Research at MU and other universitites indicates that clippings do not contribute to thatch buildup on any cool- or warm-season grasses, including zoysiagrass. Before you start returning clippings to your lawn, make sure the thatch layer is no more than 1/2 inch thick. A layer more than 1/2 inch thick will prevent clippings from coming into contact with soil microorganisms. If thatch is a problem in your lawn, use a vertical lawn mower or power rake to reduce the thatch layer. Use the thatch as a mulch or add it to your compost pile.
