Thunbergia grandiflora Augusta vine. This is the largest of all the blue sky vines with blossoms up to 3 inches across. Sometimes called Clock Vine Bengal Trumpet Vine or Indian Sky Vine. In spring this semi evergreen vine grows up to 60 feet and is covered with 3 inch wide clear blue flowers that are cup like funnels with either pale yellow or cream stripes down the center. This fast growing vine can reach the top of a large fence in a season. Hardy in zones 8a to 11 and root hardy to 20F but will freeze back at 25F. Requirements are sun to part shade and does not like to have its roots standing in water. The soft leaves are a medium green of about 3 inches with toothed edges.