The susceptibility of poverty oat grass and rough bentgrass to foramsulfuron was assessed in greenhouse and field experiments. A dose response study was conducted in a greenhouse with treatments consisting of 0, 4.4, 8.8, 17.5, 35, 70, 140, and 280 g foramsulfuron ha^-1. Field experiments were conducted using a similar dose response and also included industry standard fluazifop-P-butyl and sethoxydim applications. Foramsulfuron application rates of 4.04 ± 0.73 and 6.6 ± 1.3 g a.i. ha^-1 reduced poverty oat grass biomass by 50% in the greenhouse. In contrast, 4.4 g a.i. ha^-1 foramsulfuron caused >70% reduction in rough bentgrass biomass in the greenhouse. In the field, 280 g a.i. ha^-1 of foramsulfuron was required to reduce poverty oat grass total and flowering tuft density and >35 g a.i. ha^-1 (registered foramsulfuron rate) was required to reduce flowering tuft inflorescence number by 50%. In contrast, rough bentgrass was injured by 4.4 and 8.8 g a.i. ha^-1 of foramsulfuron and total and flowering tuft density and flowering tuft inflorescence number were reduced by all other foramsulfuron rates evaluated. Foramsulfuron application rates of 13.1 ± 2.4, 10.3 ± 1.2, and 5.4 ± 0.9 g a.i. ha^-1 reduced rough bentgrass total tuft density, flowering tuft density, and tuft inflorescence number, respectively, by 50%. Lowbush blueberry growers can consider foramsulfuron for postemergence management of rough bentgrass, but additional research is required to identify new herbicides for postemergence poverty oat grass management.