Bressingham Blue Lily-of-the-Nile. There is probably not a better hot summer perennial for the Deep South than this genus. It thrives in full sun with good drainage. And there is nothing more refreshing in our 100° heat than the cool blues of Lilies-of-the-Nile. The British tell us that this is the most cold hardy Agapanthus cultivar in existence, and it is completely deciduous. It also has some of the darkest blue flowers of the genus. Flower stalks are up to 24" high with 5-6" flower heads. Always remember to lime your Agapanthus. This will keep them flowering well from year to year. If they don't get enough calcium, they will continue to put up foliage, but will stop flowering. This is a cultivar of garden origin, but the genus Agapanthus is a native of S. Africa.