Currently, non-native sedums dominate vegetated roof landscapes in the Southeastern U.S.; however, interest in native species alternatives is escalating as citizens recognize the benefits native plants offer over non-native species. This research examines the performance of eight granite outcrop plant species in typical extensive vegetated roof conditions, over the course of one growing season, to offer new plant alternatives to conventional roof plantings. Granite outcrop plants are a threatened community occurring in the Georgia Piedmont. Species from this community may be uniquely adaptable to extensive vegetated roof conditions because of similar conditions between vegetated roofs and granite outcrop habitat. Findings suggest granite outcrop plant species may be good alternatives to non-native sedums in extensive vegetated roof plantings in the Georgia Piedmont. Four-inch depth substrate with 10% organic matter produced the most vegetation cover F(3,396) = 2.89, p = .035, and offers optimal conditions for granite outcrop planted extensive vegetated roofs.