Houston, Texas is the fourth largest city in America. With six green roofs to boast, the Appel Green Roof proprietary Perlite media inbued with Jennifer's Landscape Vitamins Granular Vitamins and Compost Tea have been the most successful green roof media types to grow full sized plant materials that bio-filter rain water in this climate. (Picture above is Sweet at the Green Roof at the Historic Humble Oil Marriott in 2004.)