Mid August-September is the best period for thatch removal, particularly if large amounts need to be removed. At this time, all dead stems and roots which accumulate throughout the fall and winter can be removed. Turf grasses can recover quickly at this time because the soil is warm and the rain is more likely to be regular. If properly de thatched, grasses will recover quickly and resume normal appearance in a short period of time. If light thatch removal is all that is required, de thatching can be done any time of the year.
Power rakes or other mechanically driven de thatching machines are usually superior to hand rakes.
Considerable force is necessary to slice or scratch into the grass mat and remove the dead material. Remove loosened material before changing directions. After thatch has been removed from the lawn, mow at the recommended mowing height. Do not increase or decrease the mowing height of lawn turf at any time during the season. There is no valid reason for changing the mowing height.