Sky Blue Aster

Sky blue aster carries a clearer, brighter blue than most fall asters manage, closer to true sky blue than the violets and lavenders the season usually offers. Symphyotrichum oolentangiense grows 2 to 3 feet tall and 1 to 2 feet wide in full sun to part sun, hardy from Zone 3 through Zone 8, and blooms the first season after planting. Loose clusters of deep blue daisies with yellow centers open in early to mid fall on arching, wiry stems, giving the plant an airy look rather than a solid mass of color. Asters are a keystone genus, and this one is a heavy draw for late-season bees, including specialists that feed on nothing else. The basal leaves are large, heart-shaped, and rough-textured, quite different from the narrow leaves higher on the stem. Sky blue aster grows wild on dry prairies, glades, and open rocky ground, so it wants full sun and well-drained soil, and it handles drought and poor ground once established. Rich or wet soil makes the stems soft and prone to leaning. It takes moderate road salt, and deer generally leave it alone.