This feature will appear in the blog throughout the year. Many plants have fallen out of favor over the years, but for the sake of bio-diversity and landscape interest they deserve to be resurrected. Today's featured plant is:
Caryopteria x clandonensis, commonly called the blue spirea
This small shrub, two- to three-feet tall by three feet wide, has become a rarity in the landscape, especially in the Midwest. It prefers full sun and loamy soil that is loose, with good drainage. In July to August, it bears blue flowers in small cymes from the axils of the uppermost leaves on wood from the current season’s growth. It is an ideal plant for the herbaceous border and, as with spirea bumalda, should be cut back in winter.
Excessive fertility can result in rampant, untidy growth. Spireas generally are tolerant of a range of PH and will tolerate a higher PH than many other species. The plant is rated at zone 6 in most horticultural manuals, but it has been planted successfully for many years in zone 5 without serious acclimation problems. It is a real showstopper when planted en masse, though it also looks good as a single plant. (I have used it as a facer plant to a backdrop planting of pink roses to great effect.) It is difficult to know why it has fallen out of favor – hardiness issues, change in landscape fashions, simple lack of familiarity with the species? Whatever the cause, this plant has a real place in today’s landscaping and deserves to be used more frequently.