Toronto's New Soil and Tree-Based Standards for Boulevards

Summary

In 2012, the city of Toronto adopted new standards for tree planting and sidewalk design for trees in the most densely developed areas of the city.  These new standards are based on the most current thinking on developing healthy trees in the most difficult areas on a major city.  The standards begin with setting new soil volume standards and seek to find solutions to the most difficult problems confronting trees in difficult spaces.  These are: providing adequate soil volumes; respecting the future growth of the trunk flare and zone of rapid root taper; getting water into and out of the soil; providing room for canopy development; and starting with quality nursery stock.  These standards had to negotiate the needs and conflicting goals of all city departments and Toronto’s numerous private utility companies.  The standards included developing new details for all aspects of the paving and features in the right of way.  Specifications for planting, soils and other critical elements were completely rewritten.  The project took almost two years to complete.

The session will outline the basic requirements of the standards and how they meet the goals of both the tree and the other right of way requirements.  It will describe how the standards process changes the look and feel of the pedestrian environment that has been engineered with trees a high priority.  The difficult process of negotiating the standards thru the various city agencies, utility companies, private sector concerns and over coming political hurdles will be reviewed. 

The new Toronto tree standards are not only an impressive accomplishment for this city, but can serve as a template for standards in other cities in Canada and the United States and developed cities around the world.