In this symposium convened to celebrate the tenth anniversary of David Harvey's Justice, Nature and the Geography of Difference, it is fitting to re-visit key themes in that seminal work, including: (1) the mutual reciprocity between social and environmental changes; and (2) the contradictions that emerge from a dialectical analysis of these changes in urban spaces. In challenging scholars to explore the spatial dialectics associated with environmental and social changes, Harvey's political and intellectual project included demonstrating the dialectical linkages between notions of justice and nature in urban environments. My work responds to Harvey's challenge by documenting how the ideological constructions of home, homeless and public green space produce and perpetuate injustices experienced materially and spatially in the daily lives of homeless people living in urban green spaces. Using Agamben's notion of bare life as my analytic framework, I explore two issues: (1) the disconnection between notions of home articulated by homeless people living in green spaces and the ideological constructions of homeless espoused by government and planning agencies; and (2) the tensions in urban green spaces resulting from homeless people who have opted to live there because all other options are not viable for them, and the ideological constructions of urban green spaces developed by the city parks department and housed citizens involved in planning for future green spaces in the city. I present the concept of ecological gentrification, which I define as the implementation of an environmental planning agenda related to public green spaces that leads to the displacement or exclusion of the most economically vulnerable human population — homeless people — while espousing an environmental ethic. I conclude by advocating a robust pluralism of home and public green spaces as an initial movement towards renegotiating concepts of justice in urban areas. I present short- and long-term strategies for resisting the displacement, exclusion and expulsion of homeless individuals from public urban green spaces with the goal of improving their material and spatial lives, and argue that such strategies require a re-imagined practice of urban ecological planning that draws inspiration from Harvey's commitment to producing spaces of justice, nature and difference.