As we build new communities, streets, and parks and public spaces we will require significant quantities of trees that can survive in an urban waterfront environment. Guided by our Sustainability Framework, our new blue edge will become an urban forest that maximizes the waterfront ecosystem by avoiding monocultures, maximizing the tree canopy and providing wind protection and shade. Beautiful, mature trees will define our waterfront helping to restore the natural beauty of our shoreline.

Waterfront Toronto is incorporating best practices for healthy trees into all of our work on the new blue edge. First and foremost, we are enhancing tree environments by positioning trees carefully, using appropriate soil, and enabling good root growth through new technologies such as silva cells. We are also working to save existing trees wherever possible and making smart choices when planting new trees such as choosing natives species and avoiding monocultures. Native

plant species are an excellent choice because they generally require much less water to thrive and do not introduce the risk of ecosystem disruption.

We are also identifying and planting trees that are tolerant to our climate and levels of urban pollution. In addition, measures will be taken to enhance terrestrial habitat including creating favourable conditions for migratory birds. All of these efforts will help to reduce the heat island effect, purify the air, improve stormwater management, and add beauty and comfort to our new neighbourhoods.

Growing trees to maturity in urban environments is difficult. New trees face many challenges including damage due to exposure, pollution and salt from winter road maintenance. While many of these issues can be overcome with appropriate species selection, research shows that the most taxing issue for all trees in the urban environment is soil compaction.

Waterfront Toronto is working with leading tree experts and employing the latest technologies to address the lack of adequate volume of soil for tree root growth. Soil under pavement is highly compacted and usually causes trees to die prematurely after seven to ten years.

New tree planting technology, which installs a tiered web of rigid boxes — called silva cells — is designed to house an average of 30 cubic metres of nutrient soil per tree. These reinforced cells provide support for the soil so it won’t compact under the weight of the pavement above. The system allows tree roots to spread and thrive resulting in healthier mature trees.