Urban farming communities often consist of many disjoint initiatives, while having a strong need to overcome their fragmentation. Community mapping can help urban farmers make better sense of their collaboration. We describe a participatory community mapping approach being piloted in an urban farming community-building project in and around the city of Tilburg. The approach combines (1) a basic community mapping language, (2) a state of the art web-based community visualization tool, and (3) a participatory mapping process to support the community-building efforts. We outline the approach being developed and present initial results of applying it in the Tilburg case.