When contractors talk of green buildings, they mean environmentally friendly and energy-saving. Add agriculture experts in the plans and "green" also means plants -- vibrant ornamental grasses, shrubs and flowers in park-like settings on the roofs of multi-storied office buildings in cities. "These green roofs actually will help mitigate problems in the urban areas like what people call having urban heat island," said Dr. Astrid Volder, Texas AgriLife Research horticulturist. "Urban areas are usually a lot hotter than rural areas, so having plants on your roof will actually facilitate cooling." See full story at http://agrilife.org/today