October Skies Aromatic Aster
Symphyotrichum oblongifolium 'October Skies', or aromatic aster, was selected for the Chicago Botanic Garden's plantings because of its intense lavender-blue color, and because it does not spread as aggressively (by rhizomes) as the species. The 1-inch blooms flower freely throughout September and October, and are magnets for butterflies and bees still seeking nectar and pollen at the end of the blooming season. The leaves are fragrant when crushed, and the small, ripe seeds are beloved by goldfinches and other small, seed-eating birds. Newly planted plants may need protection from rabbits until established, but otherwise this cultivar is insect- and pest-resistant.
(The old name for this plant was Aster oblongifolius 'October Skies'.)