A spontaneous seedling found at the Huntington Botanical Gardens. 'Indigo Spires' begins blooming in early summer and will bloom until the first frost. Calyx and corolla are deep violet-blue, resulting in dramatic color all summer long. A nice cut flower, even when the flower petals have dropped the calyx color will keep the color going! Prune back spent flowers, and cut unruly branches. Plant in partial shade. Grows 3 to 4 feet tall, 3 feet wide.