This paper details a research project and design, the Smart Forests Atlas, which expands open-data research platforms toward pluralistic and participatory practices. Working with the under-examined practice of ‘digital gardening’, the project reconfigures the open-data research platform into a dynamic and participatory space for cultivating ideas and generating content. However, we found that digital gardening could risk reinscribing existing colonial and anthropocentric practices of gardening and digital archiving. To challenge these risks, we propose six complementary design qualities that inform the design of the Atlas and could influence other open-data research platforms. We developed these qualities from a design inquiry into open-data platforms, environmental atlases, and digital gardening practices, while designing and developing the Atlas together with a digital tools cooperative. We argue that transformed digital gardening practices could advance more pluralistic, participatory, and more-than-human approaches to open-data research platforms while contributing to epistemic justice.