Caryopteris clandonensis ‘Dark Knight’ is a fetching shrub, bearing eye-catching deep blue flowers in autumn. It forms a mound of slightly toothed, grey-green leaves with silver hairs on the undersides. It’s perfect for growing in containers or towards the front of a sunny border. Its flowers are a magnet for bees.Caryopteris clandonensis ‘Dark Knight’ in well-drained neutral to acid soil in full sun. Prune plants hard after flowering to enjoy the best show of flowers the following spring.