Two cases of context-sensitive mobile computing curricula for children are shown to develop analytical understandings of how science-related sense-making talk can be supported through physical and digital environment interaction, which supports play and learning through movement. Our work investigates how proximity-based computing mediates children's engagement in scientific sense-making conversations in a botanical garden. We draw upon sociocultural perspectives on sense-making talk as well as learning on-the-move to inform our study design. Data are from children in summer camp, including field notes, photographs, and video records (26 children in Case A, 24 in Case B) in an Arboretum. Our findings illustrate that children engaged in both playful and scientific sense-making talk in two distinct curricular tasks. We provide insights into science sense-making talk patterns and pedagogical practices of integrating learning on-the-move strategies into informal education with design principles related to augmenting gardens with digital content. Our results suggest that learning on-the-move strategies influence sense-making talk and that embodied interactions within the gardens support science sense-making and role-play. We posit that designs for learner-centered mobile computing can create digital-physical hybrid spaces where learners engage each other and natural objects as they walk through community spaces.