You may have heard of the process known as lawn thatching, which is more correctly called lawn de-thatching, or lawn aeration, since its purpose is to remove the layer of unwanted material, the thatch, that lies at root level below your lawn. Dead roots, decomposing grass and other debris that is moved around by the lawnmower slowly accumulate to create thatch.
Thatching increases the amount of water and nutrients available for your lawn to consume. As thatch accumulates, it prevents water, nutrients, sunlight and air from reaching the roots of the grass. When this occurs, the grass is suffocated and starved, promoting an unhealthy and unsightly lawn. While a thin layer of thatch is beneficial to your lawn, protecting it from extreme weather and traffic, an excessive layer is damaging.
Thatching provides ample aeration for the desired grass and its underlying soil. Thatching's removal of the excessive layer of decomposing material increases air circulation, promoting healthy cell growth, improving irrigation drainage, and allowing water, nutrients and air to pass directly to the root system. Aeration reduces the potential for soil compaction and helps to control thatch development.
Insects and other pests tend to thrive in thatch areas. Removing the thatched areas disturbs the homes of these pests, forcing them out of the lawn. The process will greatly reduce, if not eliminate, infestations.
Thatching reduces the potential of grass diseases, such as leaf spot, summer patch and dollar spot. These fungal diseases overwinter in poorly aerated lawns and spread during the summer's growing season. The potential for these diseases is high in lawns that have large areas of thatched grass.