Clematis 39rouge cardinal39 is best grown in a sunny position where the single velvety red flowers with brown anthers will gradually mature to a stunning purple45red colour arguably one of the best red varieties clematis 39rouge cardinal39 will produce a striking display from july to september this late large flowered variety is excellent in borders and containers against a sunny wall or scaling a free standing obelisk height 3m 40103941 spread 1m 40339