Innovative forms of organising are a crucial pillar of post-growth transitions. Situated within a growth-based institutional context, actually existing forms of post-growth organising are ambiguous. Divisions across legal structure, market participation and sectoral focus do not suffice to single out post-growth organisations. Instead, this paper develops a more fluid notion which is based on the “thick description” of organisations. Conceptually, the paper borrows from diverse economies and practice theory literatures, allied in their appreciation of performativity. The latter in particular illustrates transition’s irreducibility to structural or individual agency and lends itself to a notion of post-growth politics: the practice of changing the rules of practice to support parallel and mutually enforcing processes of cultural and institutional change within the diverse meanings of post-growth. Studies of diverse economies remind us that market practices are only the tip of the (economic) iceberg. In conjunction with qualitative empirical data from a study of alternative economies in Stuttgart, Germany, a framework is developed to structure organisations’ diverse forms of relatedness to larger contexts. Identifying, besides economies, also communality, narratives, experience, governance and ecology as central patterns in the relationality relatedness of practices (logics), this paper proposes a structured notion of diversity to discuss the ambiguities, contradictions and compromises of actually existing post-growth organisations.