This chapter explores the utilization of social cohesion and diversity in creating more sustainable multi-cultural communities. Community greening is seen as a catalyst for sustainability-oriented social learning. Greening here is not the same as literally adding green to a community (trees, parks, gardens) – although that certainly can be a part of it – but rather as a metaphor for improving quality of life and a stepping stone towards sustainability. Social learning is introduced as a process that builds social cohesion and relationships in order to be able to utilize the different perspectives, values and interests people bring to a sustainability challenge. Although there are many perspectives and definitions of social learning it is defined here as: a collaborative, emergent learning process that hinges on the simultaneous cultivation of difference and social cohesion in order to create joint ownership, and to unleash creativity and energy needed to break with existing patterns, routines or systems. The chapter is empirically grounded in the Dutch city of Rotterdam. We use the phrase red zone to refer to parts of Rotterdam, because there are a number of socio-economic, cultural and ecological issues that could come together and escalate in ways that we have seen in similar Western European metropolitan areas such as the Paris banlieues. One of the questions we address is: How can, under conditions like these, diversity and social cohesion be used in building more sustainable practices, lifestyles and systems?