Food security is not a new concern, but has taken on new dimensions in recent years. Here we position food security in a broader context relating to the use and management of global biomass resources, and specifically the push to develop a ‘bio-based economy’. We note a growing focus on plants as a source of innovative solutions to complex problems including food security, energy security, climate change and global environmental health. However, we also note that plants are a renewable but finite resource, and propose that renewed enthusiasm for plants is resulting in an increasingly complicated ‘politics of plants,’ as competition for limited land and biomass resources intensifies—the clash between food security and energy security over biofuels being an obvious example. Plants are a common thread across many policy domains including agriculture, energy, environment, health, and industry, and as such we suggest that they might provide a focal point for joined-up thinking and governance. We identify this broader picture as an important backdrop for discussions regarding food security, and from our proposed framework develop a number of recommendations for further investigation.