Thatch can be an ongoing problem that keeps your lawn from living up to its potential. Thatch is an almost impenetrable mat of tangled, intertwined grass and other material on the ground surface. Removing thatch helps you get the best from your lawn. One problem with a thick layer of thatch is that newly sown seed will root in the thatch layer – not the soil. Thatch doesn't provide the same insulation as soil, so the roots of such plants dry out quickly, and the lawn dies. A heavily thatched lawn dries out faster so you have to water more frequently.