Associated plants include several species of Carex, such as C. scoparia, C. tenera, and C. tincta, plus Rumex acetosella, Leucanthemum vulgare, Ranunculus acris, Anaphalis margaritacea, Achillea millefolium, Phleum pratense, Vicia cracca, Juncus spp.
Owners of pet birds such as Budgerigars often use Cow Vetch as a nutritious food; the birds are especially fond of the seeds but may also eat the foliage.
Adults have been recorded feeding on flower nectar of various plants, including Vicia cracca, Salvia pratensis, Echium, Onobrychis and Thymus.
The larvae feed various plants and trees, including Betula (including Betula verrucosa), Myrica gale, Carex, Salix, Populus tremula, Rubus idaeus, Sorbus aucuparia, Vicia cracca, Rhamnus frangula, Lysimachia vulgaris, Vaccinium myrtillus and Galium verum.