How does your green roof garden grow?
Growing plants on rooftops is an old concept that has evolved from simple sod roofing to roof gardens and new, lightweight "extensive green roofs". Modern green roofs have environmental and social benefits; they can reduce stormwater runoff, improve air quality, mitigate urban heat, reduce the demand for air conditioning and greenhouse gas emissions, and provide habitat for birds and wildlife. Long-used in urban planning in Europe, green roofs are becoming more popular in North America, and new research designed to promote the integration of green roofs into current and future buildings is burgeoning. Researchers from the Department of Horticulture at The Pennsylvania State University published a study in HortTechnology that evaluated the influence of substrate type and depth on establishment of five common green roof plants.