Power rakes use rigid wire tines or steel blades to lift thatch debris and a small amount of soil to the lawn surface. The soil should have some moisture for best results. Power raking during excessive soil moisture conditions tears and pulls the turf from the soil instead of slicing and lifting the thatch debris as desired. After dethatching in the spring, apply a preemergence herbicide to prevent the potential encroachment of crabgrass. Figures 5a and 5b.
Core cultivation removes cores of soil, which modifies the physical characteristics of thatch.
Soil incorporation also enhances breakdown by improving physical properties of thatch and introducing microorganisms. Most turfgrasses growing on heavy clay or highly disturbed soils require annual cultivation to restrict thatch buildup. Core cultivation is not as effective as power raking in removing thatch debris, but it is less injurious and disruptive. Soil cores are removed during cultivation. These cores can be allowed to break down and redistribute soil throughout the thatch.