Vegetation make cities cooler, more attractive, and more energy efficient.
Five generations of the Snodgrass family have prospered at Emory Knoll Farms in Harford County. Its 365 acres have evolved from a 19th-century dairy operation to a crop farm for most of the 20th. Now Ed Snodgrass runs a 21st-century roofing business -- one that is environmentally friendly and has nothing to do with slate, tin, or asphalt.
Mr. Snodgrass grows plants that make roofs green. In the past eight years, he has supplied colorful, resilient and fast-growing plants to cover nearly 2.5 million square feet of rooftops across the US.
Green roofs insulate buildings in winter, cool them in summer, and prevent weather damage all year, said Snodgrass, who has 15 greenhouses at his farm in Street.
Snodgrass, who with his wife, Lucie, co-wrote "Green Roof Plants," a primer on the technology, lectures on the advantages of living rooftops and spoke at the World Green Roof Conference in London last fall.
His talks focus on managing urban problems with living systems, not mechanical ones.
The door to his office, once his grandfather's milking barn, has a sign that reads "Green roofs. They grow on you." The sweet smell of citrus, from orange and lemon trees in the greenhouse, wafts in.
The roof has been green for about three years and has never needed watering or fertilization, he says.
"It keeps the office cool in summer because the sun is not beating down on the roof," he says. "It is working for us, and not making us work on its maintenance."