Intercropping winter cereals into Kura clover (Trifolium ambiguum M. Bieb.) has the potential to improve forage nutritive value without reducing yields. The objective of this research was to compare forage yield and nutritive value of cereal–legume mixtures to cereals or Kura clover grown in monoculture and harvested at two different maturity stages in spring. Winter rye (Secale cereale L.), winter wheat (Triticum aestivum L.), and winter triticale (×Triticosecale Wittmack) were sown in autumn at two locations as monocultures and into herbicide suppressed and non-suppressed Kura clover and harvested for forage the following spring. Harvested at the cereal crop boot stage at Arlington, forage yields averaged 4.7, 4.8, 5.3, and 1.7 Mg ha^-1 and 3.5, 3.7, 4.1, and 2.6 Mg ha^-1 at Lancaster for mixtures with non-suppressed Kura clover, suppressed Kura clover, monoculture cereals, and monoculture clover, respectively. At the milk stage, yields across all mixture treatments increased by 46% to 115% compared to the boot stage at Arlington and by 88% to 101% at Lancaster. Kura clover in mixtures increased crude protein by 34% to 46% and in vitro true digestibility by 3% to 6%, neutral detergent fiber digestibility by 0% to 6%, and reduced neutral detergent fiber concentration by 8% to 18% relative to cereal monocultures. The nutritive value of mixtures and monoculture Kura clover was always greater than that of monoculture cereals. Winter cereals can be successfully managed with Kura clover for forage production by maximizing nutritive value with boot stage harvests or achieving higher yields by harvesting at the milk stage.