An essential task of participatory action research is to help close the policy implementation gap that leads to large discrepancies between policy frameworks and local practices. Too often, official regulations, laws and decrees fail to translate into concrete action on the ground. Loose institutional linkages between research, extension and local communities are often blamed as the main culprits for this gap. In turn, many stakeholders call for enhanced participation as a way to bring together scientists, development practitioners and local communities in negotiating competing claims for natural resources and designing realistic pathways towards sustainable development. Despite such general consensus about the value of participation, the latter cannot be decreed nor imposed. Participation is an emerging quality of collective-action and sociallearning processes. In this paper, the experience of participatory land-use planning conducted in Laos serves to illustrate a model of the sciencepracticepolicy interface that was developed to facilitate the interactions between three groups of stakeholders, i.e. scientists, planners and villagers, in designing future landscapes. Emphasis was put on developing an approach that is generic and adaptive enough to be applied nationally while engaging local communities in context-sensitive negotiations. The set of tools and methods developed through action-research contributed to enhanced communication and participation from initial consultation and cooperation stages towards collective decision-making and action. Both the activity of landscape design and the resulting patterns can be improved by incorporating landscape science in strategic multi-stakeholder negotiations.