Poa annua is a common weed found on golf course fairways, tees, and greens. There are currently no truly effective, selective controls for this species in creeping bentgrass (Agrostis stolonifera) turf. An approach that has met with some success is to reduce Poa annua infestations through the application of gibberellic acid (GA) inhibiting plant growth regulators. These PGRs slow the growth of Poa annua more than the creeping bentgrass, giving creeping bentgrass an ecological advantage that slowly increases its population. We compared an experimental GA inhibiting material, EXP-TGN4549, to the industry standards, paclobutrazol, trinexapac-ethyl, and flurprimidol on a creeping bentgrass/Poa annua golf course fairway. Trinexapac-ethyl did not reduce Poa annua plant counts during the season. The flurprimidol and paclobutrazol at label rates both reduced Poa annua plant counts by approximately 50%. The EXP-TGN4549 at the 0.56 kg/ha rate reduced Poa annua populations to the same extent as the flurprimdol and the paclobutrazol.