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 a favorable environment for pests and disease, an unfavorable growing environment for grass roots, and can interfere with some lawn care practices. Conditions favoring thatch include heavy, wet soils; alkaline, or high pH soils; and soil compaction. Thatch, the buildup of dead grass between living grass and the soil, causes trouble for your turf when it exceeds 1/2 inch thick. Excessive thatch prevents air, water, and nutrients from reaching plant roots. 

Cutting through and removing thatch improves your lawn's health. Lawns with a thick layer of thatch are more vulnerable to drought, as well as to insect and disease damage. The turf may feel springy underfoot from thatch buildup.

Poor maintenance is responsible for thatch (too much nitrogen fertilizer, shallow watering) and stress caused by poor mowing practices or inadequate watering. Sometimes we set the stage for lawn problems by trying to give the lawn good care. We irrigate too frequently and fertilize too heavily. These actions, combined with poor soil, lead to thatch build-up. That's when the problems -- from winter kill to drought, disease and insect damage -- begin.

To prevent thatch buildup from recurring, adjust the soil pH and alter your lawn care habits (excessive use of water, fertilizer, or pesticides are common causes). A lawn that is watered deeply, properly fertilized, and mowed a little on the long side will be able to fend off much common adversity.

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