Caryopteris x clandonensis 'Dark Knight' (Bluebeard)
Dark Knight' is a compact, rounded to mound-forming, deciduous shrub with upright stems bearing aromatic, ovate to lance-shaped, grey-green leaves, silvery beneath, and cymes of fragrant, deep purple-blue flowers from late summer into autumn.
Thrives in any well-drained soil. Needs a sunny position and in cold areas will need shelter. Will reach a height of 0.9m and a spread of 0.9m after 5-10 years.