|The cultivar, 'Kew Blue' has muted green leaves with a gray reverse and quite deep violet-blue flowers.
C. clandonensis is a deciduous shrub that has bright blue to purple, late summer flowers that attracts butterflies. Flowers appear on new growth, so cut back hard to the ground early
each spring. Foliage is narrow and grey-green and
is mildly fragrant as are the flowers and stems.
Thrives in moderately fertile, well-drained soil, in full sun or part shade. Grows to 3 foot wide and 5 foot tall.