A semi-intensive, 3,000 square foot green roof with six inches of growing medium, planted with mostly native species that require minimal artificial watering and provide much needed habitat for humans, birds, and insects. At the base of the Green Roof is a collection of native woodland plants featuring ferns, shrubs, sedges, and wildflowers, among others.
A Much Needed Habitat
Green roofs, also known as vegetated or planted roofs, provide habitat for plants, insects, and birds where an empty roof would usually be. They also supply added insulation and roof protection and reduce the rooftop air temperature during summer. Replacing the typical surface of a roof with plants helps combat the urban heat island effect – a phenomenon responsible for exacerbating heat waves in cities. While regular roofs release the absorbed sunlight as heat, the plants of green roofs convert sunlight and CO2 to biomass cooling the air through transpiration. Adding soil and plants to the impermeable surface of a traditional roof also means reducing runoff. Green roofs are built on top of a regular roof in layers. These include a protective layer that keeps the green roof from leaking or damaging the roof below, a drainage layer that keeps the green roof from becoming waterlogged, and a growing layer with extra lightweight soil for the roots.
Our, 8,000 square-foot green roof has many different native plant species, such as little bluestem grass (Andropogon scoparius) and prairie dropseed (Sporobolus heterolepis). Visitors can walk up the sloping roof to experience the landscape firsthand and enjoy a new view of Queens Botanical Garden. Continue reading about the Green Roof in a spring blog post highlighting notable plants.
Photo Credits: Jess Brey, illustration by Sven Johnson