As an Applied Plant Ecology student, I figured I would take the opportunity to talk about an innovative new application for plants that I had some recent hands-on experience with.
These photos were taken while I was installing green roofs in Toronto a couple summers ago. The many benefits of green roofs include providing energy savings to buildings via insulation, providing a habitat for insects, increasing inner city air quality, and helping to reduce the urban heat island effect.
One of the most common types of green roof, as shown in these photos, consist primarily of rolled out mats of succulent vegetation from the Sedum genus which are placed overtop of a high nutrient soil mix. These succulent plants are thick and fleshy, allowing them to retain water well even through dry temporal conditions. The plants are low maintenance and do not require more watering than what is provided by the regional precipitation. The rolls of succulents that we installed were deceivingly heavy, weighing around 100lbs depending on their saturation levels.
Usually, the edges of a green roof would consist of a variety of stones. These large diameter stones offer high drainage due to the large pore spaces that form between them. This drainage prevents excessive water retention and allows water to flow out of drainage holes installed on the building. This process prevents excessive weight and water volume that could potentially lead to roof leakages.
As of 2009, there is a green roof bylaw in Toronto. According to the City of Toronto, Green Roofs are required on:
- New commercial, institutional and residential development with a minimum gross floor area of 2,000 m²
- New additions to commercial, institutional and residential development where the new gross floor area added is greater than 2,000 m²
- Industrial buildings greater than 2,000 m² gross floor area
Applied Plant Ecology Winter 2020 