Plant of the Week: Blue Wood Aster (Symphotrichum cordifolium)

As we think about which species of wildflowers can tolerate dry conditions, this is an excellent choice for part-sun to shade.  It can grow from 1 to 4' tall depending on soil fertility and flowers best when given at least 3 hours of full sun daily.  The central stem is slightly reddish and somewhat hairy and it has 5" long x 2" wide leaves with a stem that are alternate.  During dry times the lower leaves will drop off the central stem. The ray flowers are typically lavender to blue and sometimes white and the central disk florets are usually yellow but turn to purple to red as they age.  There are 7 to 13 rays per flower head.  It is rhizomatous and can spread slowly via this method and also reseeds easily.  The best location is at the edge of the shade woodland garden and it works well with blue-stemmed goldenrod.  Like many of the asters, this species is a host plant for the Silvery checkerspot butterfly and bees are the primary pollinators.  It has no significant disease or insect pest problems and while not completely deer resistant, deer do not particularly like the plant.  This species makes an excellent cut flower for use in arrangements.  This is also a species, that when pinched back in the spring, will reward the gardener with an absolutely gorgeous flower show in the fall.