Black oat (Avena strigosa Schreb.) might be an attractive forage species in the northeastern United States, since it is generally more heat tolerant and disease resistant than other cool‐season grasses. Black oat is currently recommended for fall and winter production in USDA Plant Hardiness ones 8b–10a, which is beyond the northeastern United States (Zones 2a–6a). The objective was to evaluate 10 black oat breeding lines (referred to as “UF1” through “UF10”) for forage accumulation, crude protein (CP), neutral detergent fiber (aNDF), acid detergent fiber (ADF), and in vitro digestible organic matter (IVDOM) concentrations. The experiment was carried out in April–July 2022 in Pennsylvania Furnace, PA. Triticale (× Triticosecale Wittmack cv. TriCal 342) and Legend 567 oat (Avena sativa L.) were included as controls, as well as Haden oat and Gunner triticale, as regionally recommended cultivars. The forage accumulation within the black oat germplasm ranged from 364 to 864 lb dry matter (DM) acre−1, observed in UF7 and UF9, respectively, during the first harvest. During the second harvest, forage accumulation within black oat ranged from 1048 to 1408 lb DM acre−1, from UF8 and UF1, respectively. Crude protein concentrations ranged from 16% to 23% across all black oats, with no differences found within the germplasm. The IVDOM concentrations averaged 78% across all treatments during the first harvest and decreased to 66% during the second harvest. Overall, this study showed that black oat merits further evaluation as forage species in the northeastern United States, but further studies are required to address management of the species.