What is Thatch?
Thatch is the layer mostly made up of dead grass stems, roots, and rhizomes between the top layer of green blades of grass and the soil surface. A thin layer of thatch, about 1/2 inch thick or less, can be beneficial to the lawn because it helps shade the root zone and it limits weed germination, reduces water evaporation, and protects from frost damage. However, a thicker thatch layers can do the exact opposite and can prevent water, air, and nutrients from penetrating the soil, consequently reduced root growth and increased potential for drought stress. Thatch also favors fungal growth and can harbor insect pests. Fortunately for us in the Harford County area, some turf grass species, such as tall fescue and perennial ryegrass, do not produce much thatch. Other turf grass species, such as Bermuda grass, bent grass, and Kentucky bluegrass, have creeping growth habits and rapidly build thick thatch layers.
Thatch Removal
Removing the thatch layer can be done in a couple different ways which include; Aeration and Dethatching. Dethatching is done with a motorized machine that pulls the thatch layer out vertically. The machine has multiple vertical flailing blades. This leaves the debris lying on top of the grass. Sometimes this can be a very large amount of debris. The Debris will have to be removed or it can cause even more damage by suffocating the turf grass below it.
After dethatching, it can be a good time to plant grass seed in thinner turf areas.
