Perennial wild plants (PWPs) common tansy, common knapweed, and mugwort provide the greatest long-term methane yield within novel perennial wild plant mixtures. The PWPs also provide a rich nutritional resource and habitat for animals, especially pollinators. Harvesting in winter would enhance these ecosystem services. PWP biomass would then be more suitable for thermochemical conversion, like Sida, but this has not yet been reported.