What are the components of a rooftop garden?
What materials are needed for a rooftop garden?
Size: The size is variable and is determined by the preexisting roof.

Light: Six hours or more of full sun per day are needed.

Water: Due to a green roof’s elevation, the additional heat and wind present will result in supplemental watering being necessary.

Elevation/Topography: If the rooftop will be accessible to people and serve as an outdoor room, a flat roof is required. Inaccessible gardens, not used by people, could be constructed on a sloped roof.

Soil: Generally, the soil must be three to four inches thick and composed of a special, lightweight growth medium that is 30 percent organic soil, expanded clay pellets, wood chips and vermiculite.

Plant Materials: For an accessible rooftop, sun-loving native plants can be used. Annuals and plants adapted to containers may be selected. Sometimes small trees and shrubs are grown. Grasses, mosses and sedums are popular for inaccessible roofs.

Planting and Maintenance: Follow the directions from a landscape architect or horticulturist that are specific to the roof materials and plants used.

