Adapted warm season grasses have potential for both summer forage and biomass production in eastern Canada. A field study was conducted in 1995 and 1996 to determine the response of switchgrass (Panicum virgatum L.) cv. Cave-in-Rock, Pathfinder, and Sunburst to nitrogen (N) fertilization at 0, 75, or 150 kg ha -1 and three harvest schedules in a short season area. The grass was harvested at 4- or 6-wk intervals or left uncut until the end of the season. These treatments were combined in a split-plot design in each of three blocks on a St. Bernard sandy clay loam (Typic Hapludalf). Herbage yield and herbage N concentration were determined at each harvest for the cutting schedules. Herbage yields revealed a cultivar × N × harvest schedule interaction in 1996, while in 1995 only the two-way interactions between cultivar × harvest schedule and N × harvest schedule were evident (P 6-wk > 4-wk with their respective mean yields being 11, 10, and 8 Mg ha -1 for Cave-in-Rock; 10, 8, and 6 Mg ha -1 for Pathfinder and 11, 8, and 7 Mg ha -1 for Sunburst. Nitrogen concentrations increased with fertilization and varied with harvest and year, but not with cultivar. Mean N concentrations were 12.4, 13.9, and 15.4 g kg -1 dry matter (DM) for the 0, 75, and 150 kg ha -1 N levels, respectively, under the 4-wk system. Corresponding values were 10.1, 11.6, and 12.9 g kg -1 for the 6-wk system. End of season N concentrations for the uncut regime averaged 5.4, 6.0, and 7.6 g kg -1 DM in increasing order of N fertilization. The results indicate that switchgrass has potential in both grazed or hay forage systems in eastern Canada.