Caryopteris ‘Dark Knight’ is a small shrub with attractive, narrow, grey-green foliage and during the late summer months masses of pretty dark blue flowers. It’s a tough shrub, capable of taking dry conditions in its stride once established. There are many creative ways in which to use this - several against a white wall along with other similarly toned blue flowers such as Perovskia ‘Blue Spire’ or blue salvias can look decidedly Mediterranean. It also looks good as a background to perennials, such as alstroemerias, or for something different try it with Cosmos ‘Hot Chocolate’.