DTAH evaluated existing municipal tree planting practices in eight North American municipalities and consulted and coordinated extensively with multiple City departments and utility stakeholders, manufacturers and soil suppliers to produce a set of guiding principles, design details and specifications. Utility access of the design details were tested through full-scale mock-ups of emergency utility repair scenarios through soil cells and were the first of its kind in North America. The Best Practices Manual sets a new bar for tree planting, clearly linking tree health and longevity with soil volume and providing detailed cost-efficient options to achieve the target 20 to 30 cubic metres of soil per tree within the confines of a city sidewalk. Street tree planting is integrated with utilities, where soil under the sidewalk can be accommodated by structural concrete slabs or soil cells, and where trees are spaced so that they have enough soil volume to grow for 40+ years.
The study principles and recommended construction methods are currently being incorporated into the design of the public realm, and integrating with major infrastructure improvements, in the large scale redevelopment of Toronto's waterfront and the revitalization of Queen's Quay Boulevard.
