Thatch
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 1/2 inch thick) creates an environment favorable for pests and disease and an unfavorable growing environment for grass roots plus can interfere with some lawn care practices.
Thatch is a building up dead roots, lawn debris and dead turfgrass crowns. It 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, heavy nitrogen fertilizer applications or over-watering frequently contribute to thatch, because they cause the lawn to grow excessively fast.
As thatch levels accumulate to greater than 1/2 inch, lawn problems may begin, and the thatch needs to be controlled. Thatch may be torn out with a dethatcher or vertical mower.
