Managing Thatch in Home Lawns
Thatch in lawns is often misunderstood; both its cause and control. Some lawns have serious thatch problems while others do not. Thatch is a layer of living and dead organic matter that occurs between the green matter and the soil surface.
Excessive thatch (over ½ inch thick) creates a favorable environment for pests and disease, an unfavorable growing environment for grass roots, and can interfere with some lawn care practices. The primary component of thatch is turfgrass stems and roots, and accumulates as these plant parts buildup faster than they breakdown. Thatch problems are due to a combination of biological, cultural, and environmental factors.
Cultural practices can have a big impact on thatch. For example, excessive nitrogen fertilizer applications or overwatering frequently contribute to thatch by causing lawns to grow excessively fast. Avoid overfertilizing and overwatering. Despite popular belief, clippings dropped on the lawn after mowing are not the cause of thatch buildup. Clippings are very high in water content and breakdown rapidly when returned to lawns after mowing, assuming lawns are mowed on a regular basis (not removing more than one-third of the leaf blade).