Do grass clippings cause thatch?
Grass clippings are approximately 80% water. Clippings left on the lawn produce little to no thatch accumulation in the lawn. Thatch is dead bio-mass that accumulates faster than it can break down naturally. Generally this is the result of dead turfgrass plants or plant parts that have heavy, thick growth parts with more tannin in them, such as the crowns of the turfgrass plant, stolens and rhizomes. Little sticks and other debris can also build up, adding to the thatch layer.
