Solving fundamental sustainability challenges in our food systems requires political, institutional and socio-technical transformations. Indeed, sustainability transitions are needed. In this paper, we explore the role of civil society in the form of bottom–up grassroots initiatives in the transition towards a sustainable urban food system and examine their potentials, impacts and challenges in the foodshed of Münster in Germany. To this end, relevant initiatives in Münster have been researched and mapped according to explicit criteria, and case studies have been compiled for two of them using questionnaires, interviews and desk research: a community-supported agriculture (CSA) farm Entrup 119 and an urban gardening initiative GrüneBeete e.V. The results indicate that many initiatives in Münster focus on education and information, i.e., raising awareness, rather than offering material alternatives. Six initiatives were studied in more depth using desk research and a questionnaire. Key leverage points identified by the initiatives are in policy, education, networks and communication. Two of these were studied as cases. We see these transition pioneers as paradigmatic role models, providing room for experimentation, social learning and empowerment.