There are just six species in the genus named Caryopteris, and one is the small shrub many of us enjoy in our gardens. It has frothy, rounded blue flower clusters in midsummer. Its common names are bluebeard, blue mist shrub, and blue spirea. Sometimes it is described as a sub-shrub, as its soft aromatic top growth dies to the ground in winter.
‘Blue Mist' has pale blue blooms, while ‘Dark Night' has silver leaves and violet-blue flowers. ‘Worcester Gold' has the added benefit of golden foliage, which contrasts with the purple-blue blossoms in zones 4-9. Grow in full sun in well-drained soil.
Caryopteris ‘Longwood Blue' is a classic that has upright silvery growth, fragrance, and bloom from midsummer to mid fall, and ‘Little Miss Sunshine' has golden foliage, a compact rounded shape, and masses of fuzzy blue flowers. ‘Beyond Midnight' has darker stems and flowers, darker blooms, and they are especially irresistible to pollinators. Also try ‘Sapphire Surf', which has masses of dark royal-blue blooms in zones 5-9.
Caryopteris can be grown singly, in multiples, or as a long hedge for maximum impact.