literature review includes : school ground greening research (learning, social & behavioural development of children and adults, restoration and behavior, play, environmental awareness and stewardship, health, health recovery, illness prevention and health promotion, safety) ; critical environmental education ; school ground greening in canada.as school ground greening becomes more common in schools around the world, researchers from a number of disciplines and fields have begun to investigate the potential outcomes of the differing approaches, traditions and contexts of these projects. much of the research on these initiatives has been performed within a single school, m aking it difficult to understand the nature of the impacts across a large sample of schools. in this study, i explored school ground greening projects at a school board level of analysis, using the toronto district school board (ontario, canada) as my site of investigation. i used a mixed-methods approach: 1) 149 questionnaires were completed by administrators, teachers, and parents associated with 45 school ground greening initiatives in the school board; 2) 21 in depth follow-up case studies were conducted at 5 schools across a range of socio-economic statuses; and 3) 6 interviews were conducted with school board administrators and an evergreen employee. in this dissertation, i work within a critical environmental education framework to present and discuss findings of several key areas, including: 1) the profiles of individuals and schools who are involved in school ground greening projects; 2) the profiles o f the actual projects; 3) the process of greening school grounds; 4) the impacts of green school grounds; and, 5) the key limiting and enabling factors for these initiatives. i conclude with a discussion of future research priorities.