Conservation

Native Green Roofs

With concern growing about climate change and the urban heat island effect, green roofs are seen as one way of mitigating both threats. Adding plants to roof top environments bring such benefits as shade, insulation for the building below and reduced stormwater runoff. On a green roof, the plants and growing medium or soil take the place of the asphalt and gravel or shingles on the roof. The roof includes a waterproofing layer, a drainage layer, the growing media and the plants covering the surface.

Green roofs can help cities and improve the quality of the air and reduce stormwater runoff while also improving the energy efficiency of the building beneath them. Wildflower Center projects use regionally appropriate native plants, preserving the natural heritage of the region.

Reduction of heat island effect - The heat island effect is the difference in temperature between urban areas and the surrounding countryside caused by a lack of vegetation and a large number of reflective surfaces that absorb heat. Wildflower Center research shows that green roofs can be up to 80 degrees cooler than adjacent buildings with traditional roofs.

Reduction of storm water and pollutants - Green roofs retain and filter storm water through vegetation. In areas where rainfall contains significant pollution loads, green roofs should be able to improve the water quality of the stormwater. Green roofs also help air quality by filtering pollutants from the air while adding oxygen to our urban environments.

Increased energy efficiency of building - The cooling and shading properties of a green roof can decrease the amount of heat flowing into a building and can significantly reduce air conditioning requirements.

Wildlife habitat - Particularly in urban areas, green roofs can create valuable habitat.

Aesthetic Value - Green roofs covert typically wasted space into valuable aesthetic and recreational amenities.

Longer lifespan - Plants and other layers on the green roof help protect the roof membrane from extreme temperatures, hail, foot traffic, and direct sunlight. This can prolong the life expectancy of the roof. The initial cost of installing a green roof, which is higher than traditional roof systems, can be partially offset by reduced roof replacement costs in the long run.

Species List from Wildflower Center Research