Single-year intercrops of winter cereal grains and forage legumes have an important contribution to make to North Central USA cropping systems, and improvement of component yields through informed cultivar choice or cultivar improvement could increase profitability and ease farmer adoption. This study sought to characterize winter cereal grain genotypes associated with high or low yields of each intercrop component and to identify cereal grain traits of potential utility in breeding for intercrop performance. Twenty-five winter wheat (Triticum aestivum L.) and 17 winter triticale (X Triticosecale Wittmack) lines were intercropped with red clover (Trifolium pratense L.) and evaluated for cereal grain canopy characteristics (including light interception, leaf area index [LAI], and leaf angle distribution), cereal grain morphology and phenology (height, tiller density, and heading date), and component yields (cereal grain yield and clover forage yield). Over two years, a tradeoff between grain yield and forage yield was observed in wheat (r = -0.43), but not in triticale. Wheat canopies with high light interception, high LAI, and highly horizontal leaves predicted not only low clover yield (r = -0.53, -0.59, and -0.54, respectively), but also high wheat yields (r = 0.68, 0.47, and 0.45, respectively). Triticale canopy characteristics displayed a less consistent pattern of relationship with component yields. Height was a predictor of low clover yields (r = -0.50) in triticale. Results did not clearly identify any cereal grain traits for potential use as criteria in indirect selection for component yields.