Thatch is a layer of leaves, roots, and living and dead stems that is situated between the grass and soil. When grass is properly mowed, the clippings decompose quickly and add very little to the thatch layer.
WHAT IS IT:
Thatch is a layer of tightly knit plant material. Soil is generally not present within the thatch layer and holds very few nutrients. The thatch layer acts very much like a sponge, absorbing water quickly. Most lawns require a thatch layer of between ½ to ¾ of an inch. This layer protects the turf grass roots from the heat of the day. It also aids in reducing soil compaction in high traffic areas. When thatch becomes thicker than 1 inch, this is when problems can occur in a lawn.
LAWN PROBLEMS DUE TO THATCH:
When the thatch layer becomes thicker than 1 inch in depth, turf-grass will begin to utilize this area for its root system. Because thatch holds very few nutrients, the root system suffers. As the thickness increases, watering becomes increasingly difficult to do properly. The thatch acts like a sponge and absorbs almost all of the water that is applied to the lawn, leaving little for the root system of the grass to use. Any thatch over 1 inch is also a great place for insects that feast on your lawn.
CURING THE THATCH PROBLEM:
Deep core aeration is the number one way to prevent thatch buildup. The machine pulls 3-inch plugs from below the thatch layer. These holes allow water and air to reach deeper into your soil structure. If your thatch layer is over 1 inch in depth, one remedy is to top dress your lawn. By applying 1 inch of topsoil on your lawn in the spring and fall, the microorganisms should be able to break down approx ¼ inch of thatch per year. Thatch which is 3-4 inches in depth really has no solution other than to strip off the sod layer including the thatch, and either re-sod or re-seed.