Aster oblongifolium (aromatic aster) is a tough native perennial that brings dependable late-season color and pollinator activity to sunny spaces. You will get a dense, mounding plant with narrow, aromatic foliage and clouds of small blue-purple flowers from late summer into fall. At maturity it typically stands 12-36 inches tall and can form a broad, self-supporting clump with time, making it a great choice for the front of a border, a meadow-style planting, or along a walkway.
Give it full sun and well-drained soil for best performance. Once established, it handles dry conditions well and adapts to lean, rocky, or otherwise challenging sites where many perennials struggle. If you want a tidier, more compact shape, you can shear the plant back lightly in early summer; this helps encourage branching and can improve the overall mound and bloom display later in the season.
Aromatic aster is valued for wildlife: the flowers are attractive to butterflies and other pollinators, and the seed can benefit birds. It is also noted for resistance to browsing by deer and rabbits in many settings. Keep good air circulation to reduce the chance of powdery mildew, and avoid consistently wet, poorly drained spots. After flowering, leave stems standing through winter if you can; many beneficial insects use hollow stems for nesting, and you can cut back in spring when new growth resumes.