Aromatic Aster is a tried and true source of stunning blue color in the late season perennial garden, where it is seen to play dramatically against rich fall yellows and golds and oranges. It is shrub-like and bushy, compact, reaching 1-2+ feet and usually totally covered in blooms for up to 2 months if grown in the full sun. Flowers are daisy-like, lavender to deep blue with yellow centers turning reddish purple with time. Aromatic Aster is reported in only one county in NC, up in the mountains. It is much more common in the midwest, between the Rockies and the Appalachians, where it found in mesic to dry gravel prairies, dolomite prairies and limestone glades. Hence, it is happiest in well drained soils and can tolerate lean soils and a wide pH range. It is its most spectacular in full sun. It is easy to grow; indeed, it should be cut back early in the season to control its height, as well as just after flowering to control its seed dispersal, and runners will also produce offspring if not deterred (all the more for your friends). This plant will reward gardeners by drawing a very large number of pollinators to its dramatic late-season display. The USDA plant distribution map linked below is for the species.
‘October Skies’ and ‘Raydon’s Favorite’ are two super-showy cultivars of Aromatic Aster that have proven rewarding in the garden. Although the precise bloom time depends on location and weather, a Chicago Botanic Garden study found ‘Raydon’ bloom period to be a bit longer (early August to early November) than that of ‘October Skies’ (early August to late October). The same study listed flower coverage of ‘Raydon’ slightly greater – “excellent” for ‘Raydon’ vs. “good” for ‘October Skies’. ‘October Skies’ is a little shorter than ‘Raydon’ (on the order of 18 inches vs. 24 to 30 inches for ‘Raydon’) and the flower color, on a scale from cornflower blue to lavender, is more blue than that of ‘Raydon’. Both make outstanding late fall statements in the garden. The large number of pollinators (butterflies, bees and other beneficials) attracted to these plants adds to the joy of the garden community. Interestingly, the Chicago Botanic Garden is sponsoring a citizen science study comparing the cultivars to the species with respect to their attractiveness to pollinators! Interested? See Budburst.org, Nativar Research Project!