Climate adaptation presents significant challenges for small and medium-sized municipalities (SMM) that often operate with limited resources and expertise. However, well-designed and organized public participation can not only address these challenges but also build citizen capacities that are crucial for future adaptation projects. Building on existing studies on the relationship between the design and effectiveness of public participation processes, we address the question how effective public participation in climate adaptation can be designed in SMM particularly. Analyzing two German case studies of voluntary citizen engagement aimed at improving urban green infrastructure, we find that social learning with a focus on co-ownership and citizen empowerment, and citizens’ identification with the local context are important overarching objectives that have gained insufficient attention in the literature. We argue that social learning and local identification can become catalysts for achieving a wide range of participation objectives and addressing the particular challenges faced by SMM.