Late harvest of corn silage can limit the ability to properly establish cover crops in the fall. Interseeding cover crops or earlier corn harvest can help get cover crops seeded earlier and help increase the overall benefits of the cover crop. In this trial, our goals were to evaluate the effect of three cover crop seeding dates and a variety of cover crop mixes for biomass production and percent cover. In order to evaluate how cover crops may fit into a corn silage system, we also evaluated three corn varieties at 85, 96, and 110 relative maturity (RM) for yield differences.