Caryopteris GRAND BLEU

A compact form of Caryopteris, invaluable for adding a blast of late summer and autumn colour to both borders and pots. It's very hardy and easy to grow, and it looks sublime when the deep bluish purple flowers open from bud.
 
Once established, they’re drought-tolerant and low maintenance. In early spring, cut back all flowered stems hard to a low, woody framework to encourage strong new growth.