Aromatic Aster

Aromatic Aster is one of the best perennials for carrying a garden into the very end of the season, covering itself in violet-blue flowers when most summer color is already fading. Symphyotrichum oblongifolium grows about 1 to 3 feet tall and wide, building a dense, bushy mound that looks fuller and more self-supporting than many fall asters. The stiff branching stems help it hold that rounded form through the entire season. This is our favorite perennial for dependable fall color in a dry, sunny spot.This native perennial from the central and northeastern United States has fragrant foliage when crushed, fibrous roots, and rhizomatous spread that allows it to gradually fill in as a loose ground cover. Its flowers open blue to purple with yellow centers, then age to reddish purple. The blooms are valuable to butterflies and late pollinators, and the seedheads offer interest for birds after flowering. Use Aromatic Aster in pollinator beds, dry meadows, sunny borders, gravel gardens, or on slopes requiring drought tolerance and erosion control.Aromatic Aster CarePlant Aromatic Aster in full sun in well-drained soil with a neutral to slightly alkaline pH; it will also handle sandy or clay soil if drainage is good. Dry to medium moisture suits it well, and lean ground often helps it stay more compact. Avoid rich, wet sites that can lead to soft growth and mildew issues.Water regularly while the plant is establishing, and reduce watering once the roots settle in. Established plants are quite drought tolerant and usually need extra water only during prolonged dry spells. Fertilizer is rarely needed, and too much feeding can encourage floppy growth instead of a dense fall display.A light trim by no more than half in late spring or by June can help keep plants thicker and more rounded by bloom time. After flowering, cut stems back in late fall or leave some stems standing for overwintering insects and stem-nesting bees. Older clumps can be thinned or divided in early spring if they spread beyond their space or begin to open in the middle.Aromatic Aster SpacingSpace Aromatic Aster about 18 to 30 inches apart, depending on how quickly you want plants to form a continuous ground cover. For containers, use a pot at least 16 to 18 inches wide with sharp drainage, and keep it in full sun for the strongest flowering.Pair Aromatic Aster with goldenrod and little bluestem for a native-style planting that carries structure and bloom deep into fall. In containers, combine it with zinnia and verbena for a late-season mix that keeps pollinator activity and color going strong.