The increasing need for biomass for energy and feedstocks, along with the need to divert organic methane generating wastes from landfills may provide the economic leverage necessary to return this type of marginal land to functional and economic use and is strongly supported by policy at an European Union (EU) level. The use of land to produce biomass for energy production or feedstocks for manufacturing processes (such as plastics and biofuels) has, however, become increasingly contentious, with a number of environmental, economic, and social concerns raised. The REJUVENATE project has developed a decision support framework to help land managers and other decision makers identify potential concerns related to sustainability and what types of biomass re-use for marginal land might be possible, given their particular circumstances. The decision-making framework takes a holistic approach to decision making rather than viewing biomass production simply as an adjunct of a planned phytoremediation project. The framework is serviceable in Germany, Sweden, and the United Kingdom. These countries have substantive differences in their land and biomass re-use circumstances. However, all can make use of the set of common principles of crop, site, value, and project risk management set out by REJUVENATE. This implies that the framework should have wider applicability across the EU. This paper introduces the decision support framework.