Learning about sustainability is now understood to be an important part of early childhood education. An important knowledge area associated with sustainability is biodiversity. Learning about biodiversity helps young children understand the importance of relationships between living and non-living things and local habitats. This type of knowledge is a necessary basis for the formation of attitudes that are respectful of the environment. In this paper we share the findings from research that examined three different types of play-based learning, including open-ended play, modelled play and purposefully framed play. We look at how these play types were understood by teachers to support learning and teaching about biodiversity in early childhood education. We define play-based learning using Wood and Attfield’s concept of pedagogical play, and consider which of these play types connects most strongly with the Vygotskian-inspired idea that content provides a context for broadening children’s learning experiences in meaningful ways.