Prior children’s environments behavior studies suggest that gardens may encourage health and development. Mixed evidence remains, however, as to what specific elements best allow for learning to occur within natural children’s environments. It is hypothesized that children’s garden designs with greater diversity, access, and exploration of “wild nature” may improve both physical development and environmental competence. Furthermore, children’s participation and preferences for such spaces may influence design. Through a case study analysis, this study compares garden design processes and garden mission statement themes through outcomes of design elements and children’s play behavior in relation to key indicators for environmental competence. More specifically, the independent variables of mission statement themes (“participatory design and empowerment”, “accessibility and inclusiveness”, “children’s health” and “environmental education and interaction”) are evaluated for their relation to children’s participation and design features of direct natural contact, diversity of play affordances and usability. This study’s findings suggest that child participation in children’s gardens may be associated with direct natural elements preferred and used by children in garden designs. Furthermore, if elements are accessible and child-scaled, children’s interaction with these natural spaces may be more successful. Recommendations concerning best practices among the twelve children’s gardens in this post occupancy evaluation are also provided.