Butterfly Bush Empire Blue A large flowering shrub with rich violet-blue flowers with an orange eye. Buddleja davidii Empire Blue good shrub for late Summer colour. Attractive to butterflies and bees. Prune hard to control size, shape and encourage fresh flowering growth, best done in early spring, but additional partial pruning can be done after flowering in autumn. Site: Tolerates coastal exposureSoil: Well drained soils, tolerates drought once establishedPosition: Full sunSeason of Interest: Violet-blue flowers in late SummerHardiness: Fully hardyHeight: 6ft (2m) Spread: 6ft (2m)