Societal issue and theoretical background: The sustainability of human societies relies on the intergenerational transmission of capital stocks, whether natural, social, or economic. With ever more competition for economic resources, the sustainability of societies must increasingly focus on the mutual reinforcement of social and natural capitals. This perspective is particularly relevant for peasant agriculture, under constant threat of social and economic exclusion, but whose social and natural capitals remain important though often underused by the peasants themselves. The concepts of commoning and social capital are useful for addressing these issues and activating biocultural heritage from an inclusive sustainability perspective. Objectives and methods: We seek to understand how peasants organize themselves to collectively achieve social and economic inclusion goals that could promote their sustainability and resilience in the face of economic constraints. Using field surveys and participatory-action research, we analyzed the social, economic, and environmental factors that foster the emergence and sustainability of producer organizations and their value chains. We did so in three peasant organizations in Argentina, Bolivia and Chile, which share a common starting point around valorisation of traditional quinoa crops, but vary greatly in terms of size, internal dynamics, and subsequent organisational trajectories. Results: The successes and challenges of the social innovations implemented in the three cases studied provide lessons on how farmers mobilise their social capital and harness the resources of their cultural and natural capital to achieve inclusive sustainability. While some lessons remain context-specific, others appear to be independent of the size and place of the organizations, and several demonstrate the importance of the social interactions maintained both within the organizations and with the end consumers.