Society’s participation in decisions regarding land planning and management is essential for reaching viable and long-lasting solutions. The success of forest plans depends on the involvement of different stakeholders. In turn, stakeholder involvement depends on the representativity achieved in public participation in the development of the plan. The first stage, diffusion, is the key element in the process. This paper describes a methodology for the diffusion stage that obtains six times more participants than a similar process. Its aim is to achieve stakeholder representativity in the forestry sector in forest planning at a subregional level. The methodology is validated and applied in a municipality of Galicia, north-west Spain. It is evaluated in terms of efficiency considering the effort in each stage and the results achieved.