Picture of a 'Longwood Blue' bluebeard (Caryopteris x clandonensis 'Longwood Blue'). Caryopteris is a drought-tolerant deciduous shrub that reaches a height of 3’ x 4’ and a spread of 2’ x 4’. While Caryopteris can be grown in zones 5-9, in zone 5 and 6 it should be treated as an herbaceous perennial; cut above-ground growth back in winter, and await its rebirth in spring! Also called “blue mist” or “blue spirea,” its prominent features are its dense clusters of fragrant bluish-lavender flowers and its silvery-gray foliage. Flowering begins in late summer and continues into autumn. The blooms of Caryopteris attract butterflies. Because of its healthy height, Caryopteris is a good choice for the back row of a bed of perennial flowers.