The reduction of the thatch layer can be accomplished by either mechanical or biological means. The mechanical method for thatch removal involves a de-thatcher (or vertical mower) which has a series of blades which penetrate the thatch layer and go into the soil. The thatch layer is torn up by the blade action of the machine. Debris can then be raked off the lawn and removed from the site. De-thatching of home lawns may need to be done about every five years, depending on the grass species in the lawn.
The topdressing of lawn areas also aids in the control of thatch production. Topdressing is simply applying a thin layer of soil to the surface, allowing soil to be located near the actively growing grass. This close contact allows soil microflora to degrade the senescent plant tissue present in the thatch layer. Topdressing is usually practiced after a core aeration program.
Amendments can be applied to the thatch layer to promote degradation of the thatch layer. The type of amendment used to reduce thatch is influenced by the root zone and soil profile. This process can be slow and works best if the thatch layer is not very large. For the thickest layers, the thatch is best removed first through de-thatching. Soil pH and soil moisture are always critical in the activity of the microflora and the subsequent degradation of the thatch layer.