Greenhouse horticulture can play a major role in Flemish rural development, regional economy and employment. However, the sector deals with structural problems. Scale increase of greenhouse firms is required for economic reasons, but high investments and risks make this quasi unsupportable for individual farmers. Clustering greenhouses into greenhouse parks is a possible way out. Through collaboration and mutual material exchanges, firms enjoy scale effects and eco-efficiency is enhanced without individual enlargement. The government is planning pilot projects to investigate possibilities of greenhouse parks in Flanders. Obviously, many obstacles are faced, such as spatial planning, coordination of policy levels and institutions and interactions with different stakeholders, e.g. local people, environmentalists, the distribution sector. Moreover, the mere set-up of such a high impact process is a challenge. We look at similar projects, implemented in the Netherlands in order to obtain a better view on possibilities, critical success factors, triggers and threats for greenhouse parks in Flanders. Dutch cases of successes and failures are explored by case study research. After the first data gathering round, only preliminary results are presented. Different concepts such as transition and system innovation are used as theoretical lenses in the analysis. In a later phase of the research, information and lessons learned from Dutch projects will be combined with research data of Flanders. First results indicate the importance of “Related activities in the neighbourhood”, “Land”, “Financial conditions”, “Role of different policy levels”, “Support of stakeholders”, “Collaboration” and “Process specific parameters”.