How can radical grassroots alternatives organize (for) a broader social transformation of the economy and society? In this paper, we address this question by examining two research streams that see the collective action of civil society as a core driver of processes of progressive social change: research on prefigurative organizing and civil society research. But while both bodies of literature generally embrace the transformative power of civil society, neither considers more thoroughly what it means to organize for social transformation. Building on the concept of civil society as civic action and the multi-political approach of prefigurative organizing, we show how a combination of the two allows for a more advanced understanding of social transformation from below. While the cross-sectoral notion of civic action provides a normative basis for prefiguration and underscores the relational perspective on prefiguration, the multi-political approach of prefigurative organizing highlights the organizing of social relations between a variety of actors across societal spheres. We characterize social transformation from below as a civic project of prefiguring alternatives and illustrate our conceptual considerations by turning to alternative food movements. Recent developments in both food policy councils and community-supported agriculture show how these movements seek to initiate large-scale change by forming multi-political and cross-sectoral alliances beyond their own initiatives and narrow communities.