Green alleys are micro-level greening projects that transform alleys into green infrastructure and space for citizen appropriation. Despite an abundant literature on North American green alleys, knowledge about the governance of these projects remains limited. This research addresses some of these gaps by examining the programs implemented in three cities in Quebec (Montreal, Quebec City, and Trois-Rivières) and by analyzing how citizen participation interacts with the framework set by local authorities. We mobilize the concept of 'hybrid governance,' which refers to collaborative processes between governmental actors (local authorities) and non-governmental actors (citizens, NGOs) for the planning and management of urban green infrastructure. This leads to the following questions: How does the governance of green alleys vary in these three cities? What are the benefits and limitations of the 'hybrid' governance of green alleys? Multiple data sources were collected through field observations, surveys, and interviews with local stakeholders (in the summer of 2022). Our results reveal the relationships and arrangements among three groups of actors (residents, NGOs, municipality) throughout the development of green alleys. We highlight the significant role of citizens and NGOs in the success of the projects and underscore the potential risks of leading to exclusion processes. This research provides valuable insights for the scientific community and for municipalities, NGOs, and citizen groups, to improve environmental equity and the sustainability of projects over the long term.