Dethatching may be necessary, some years, when there is excessive buildup of the thatch layer. Thatch is the tightly interwoven layer of living and dead stems, leaves and roots that exist between the green blades of grass and the soil surface. Early stages of thatch development is actually beneficial, when it measures less than 0.5 inches in thickness. Thin layers of thatch help the wear tolerance of turf, reduce weeds, and reduce water evaporation. Your Extension Office can guide you to the best thatch management for your type of turfgrass.
Turf aeration is necessary if soil is heavy or compacted or thatch buildup is a problem.
A machine forces little hollow tubes into the ground and brings up small cores of soil, which are left on the top of the surface. This is done when the soil is moist, not overly dry or wet. This brings necessary oxygen to the roots along with water and nutrients. Spiked roller machines that simply punch holes into the ground may improve water retention, but unfortunately they increase compaction of the soil. Mowing The major causes of lawn deterioration are mowing the grass too low and mowing infrequently.