Plant growth regulators (PGRs) are applied to economically significant turf on golf courses to control height, reduce frequency of mowing operations, and enhance playing surface consistency. This study compared Anuew (prohexadione-calcium), Primo Maxx (trinexapac-ethyl) and experimental PGR NAI-20026 on turfgrass growth and quality parameters on a mature bentgrass/annual bluegrass greens height stand of turf. On many occasions throughout the experiment, PGR treatments significantly reduced turfgrass growth when compared to the untreated control and improved turfgrass quality and colour ratings. A rate effect was also detected in the experiment and NufTE (experimental NAI-20026) performed similarly to Primo on both the GDD and 4-week application schedule and often were ranked the same for many parameters throughout the experiment. No stress symptoms (yellowing, etiolation) were observed on the putting green turf in response to PGR application during hot/dry weather at any point during the experiment.