AbstractBlack oat (Avena strigosa Schreb.) is a cool‐season annual grass with Mediterranean origin. In contrast to other cool‐season grasses, black oat is more heat tolerant and disease resistant, making it an attractive option for the US upper Midwest, since it can be utilized during summer, when there is decreased productivity of cool‐season forages due to photorespiration. Black oat is recommended for USDA Plant Hardiness Zones 8b–10a, far away from the upper Midwest (zones 2a‐5b). The objective was to evaluate 10 black oat breeding lines (referred to as ‘UF1’ through ‘UF10’) for herbage accumulation, crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and in vitro digestible organic matter (IVDOM) concentrations. The experiment was carried out on May–July 2021 and 2022 in Stratford, WI. Triticale (x Triticosecale Wittmack cv. ‘TriCal 342′) and ‘Legend 567′ oat (Avena sativa L.) were included as controls, as well as ‘Ogle’ oat as a regionally recommended cultivar. Herbage accumulation differed by treatment (P = 0.002) and averaged 5900 lb acre−1 among black oat lines, with ‘UF3’ and ‘UF10’ having greater herbage accumulation than oat checks Ogle and Legend 567, and Trical 342 triticale. Crude protein concentration of UF7 and UF3 was 8.5 to 9.5%, respectively. The IVDOM concentrations were above 58% for all black oat. Results indicate certain black oat have the potential to provide forage resources during the early summer in the upper Midwest, but further studies are warranted to evaluate how to best manage this species into cropping or pasture systems in the region.