The City of Toronto has recently released its guidelines to biodiverse green roofs. Their recent guide provides design strategies for encouraging diverse plantings. The guide's recommendations include the following:
- Increasing the depth of the 'growing media', the green roof version of soil),
- creating mini- hills on green roofs to provide for a greater diversity of plants and animals
- Providing 'perched habitats' and water features, such as bird baths, to encourage flora and fauna
- Providing nesting opportunities
- Designing for bees (including honey bees) and other pollinators
The full report can be found here.