Agriculture in Switzerland is confronted with challenges concerning economic efficiency, food sovereignty, ecology and biodiversity. Furthermore agriculture should contribute to decentralized settlement of Switzerland. The project City Farming wants to figure out whether it is possible to uncouple these tasks and whether Urban Agriculture (UA) may contribute to it in an urban environment. The sustainabiltity of City Farming is examined with four exemplary case studies. The focus of the studies is on the social and societal dimension of sustainability – related to the companies, as well as to their social and public environment. How is social capital (SC) linked to business success? How does SC contribute to positive externalities of the business? The results are discussed in terms of innovative entrepreneurial strategies as well as in terms of the spatial effects of these initiatives for a sustainable and edible city.