Thatch Control on Creeping Bentgrass Turf

The effectiveness of thatch control practices commonly employed in Ontario on Penncross creeping bentgrass turf maintained as a putting green was evaluated from July 1976 to October 1979. The most effective treatments were coring and vertical mowing followed by topdressing, and topdressing alone. The least amount of winter injury occurred in plots where coring was followed by topdressing. Coring reduced thatch accumulation more than did vertical mowing. Vertical mowing increased winter injury and annual bluegrass content in the plots more than did coring. Thatch accumulation was less at the 5-mm than at the 8-mm mowing height. Nitrogen treatments of 2 and 4 kg N∙100 m−2 did not influence thatch accumulation.