Dark Knight Bluebeard

Dark Knight is a rounded, deciduous Caryopteris × clandonensis shrub with aromatic foliage and deep blue-purple flowers. The Royal Horticultural Society describes its profuse late-summer and early-autumn bloom and lists the exact cultivar for bees and other pollinating insects; the University of Connecticut also distinguishes its deeper blue-purple flowers from Blue Mist. ## Form and flowering The [RHS profile](https://www.rhs.org.uk/plants/101641/caryopteris-x-clandonensis-dark-knight/details/) gives an ultimate height and spread of 1–1.5 m after five to ten years, with full sun and well-drained soil. Its size range differs from the current 0.8 m dimensions and the University of Connecticut’s 2–3 ft height guidance for the broader hybrid. Those sources reflect different growing contexts; the existing points remain plausible against the documented variation. The existing 2–3 ft labels are converted to 24–36 inches because the entire range is at or below 3 ft. ## Siting Place the shrub in full sun and well-drained soil, where its late flowers can extend the season in a mixed border or pollinator planting. The [University of Connecticut profile](https://plantdatabase.uconn.edu/detail.php?pid=90) notes that Caryopteris dislikes wet roots and flowers in August; local timing varies. ## Mature size Allow for a rounded shrub that may grow larger than the current catalog points. The RHS reports 1–1.5 m at maturity, while UConn describes the hybrid’s typical height as 2–3 ft. ## Maintenance Provide drainage and use local Caryopteris pruning guidance. The reviewed sources establish the flowering window and growing conditions but do not specify a cultivar-specific pruning date.