Bluebeard, also called blue mist spirea, is technically a woody shrub. However, it loses leaves in the winter and usually dies back to the ground every year, so it is often treated as a perennial. It mixes very well with other sun-loving perennials and is great for fall flower color.
Description of bluebeard: Opposite leaves are 3 inches long and narrow. The undersides are grayish-white. Blue-purple flowers are formed toward the top of each stem in late summer or early fall. Plants grow 3 to 4 feet tall and 4 feet wide.
How to grow bluebeard: Full sun and well-drained soil are best for this perennial. It does not need rich soil or extra moisture. Blue mist spirea is frequently used in water-conserving landscapes in western states. Do not cut back stems in the fall or winter. Wait until you see new growth emerge in the spring, then cut back just above that. Plants spread by way of underground runners.
Propagating bluebeard: Take stem cuttings in spring or early summer.
Uses for bluebeard: Incorporate this perennial as you would a small shrub. Blue mist spirea can be planted singly or in groups of three. It mixes well with yellow flowers that bloom at the same time of the year, such as orange coneflower and goldenrod. It blooms at the same time that monarch butterflies migrate and butterflies find it an irresistible nectar source.
Bluebeard related varieties: 'Blue Mist' has gray-green leaves and light blue flowers. 'Heavenly Blue' has dark green leaves and deep blue flowers. 'Longwood Blue' has silvery foliage and sky blue flowers.
Scientific name for bluebeard: Caryopteris x clandonensis