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 < 0.05). Total yield ranking for the harvest regimes was uncut > 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.