This study examines the conversations of 41 student teachers during visits to a designed rainforest in a greenhouse in a botanical garden in Sweden. The aim of this study is to explore the multimodal affordances of the rainforest for student teachers’ negotiations, and through this obtain an understanding of the potential this environment has for teaching and learning about plants, biodiversity, ecology and life on Earth. Data for this exploratory case study was collected through observations as well as audio recordings of interactions between student teachers. Data was analysed using multiple tools, including thematic analyses and social semiotics. The results show that the walk-through in the rainforest and the encounters with plants awaken curiosity, raise questions and bring about hypotheses. This has implications for and informs teaching about plants and the importance of plants for life on Earth.