Aromatic Aster (Symphyotruchum Oblongfolium)

Local Name: Aromatic Aster

Botanical Name: Symphyotrichum oblongifolium

Family: Asteraceae

Native Status: Dakota County Native 

Landscape Archetype: Prairie, Edgeland 

Life Cycle: Perennial 

Sun Exposure: Full sun, part sun (tolerates a surprising amount of shade)

Soil Moisture: Dry to Mesic

Soil Type: Loam, Sand, Gravel, Silt

Height & Width Range: Height: Knees (12"–24") Width: 24"–48", forming broad, mounded colonies over time.

Bloom Color: Purple and Gold

Morphology Notes: A sprawling dense mound of woody-esque stems with many narrow, oblong, and rough, bristly leaves. When crushed, the foliage emits a pleasant aromatic scent. The latest of late season blooms erupt in a spectacular show of purple daisy flower with golden yellow centers. The root system is fibrous with short rhizomes that allow for gradual colony expansion. 

Fruits and Seeds: Dry achenes with white pappus ripening in late fall. Not edible. Not known to be toxic. Seed heads persist modestly but are not strongly ornamental.

Habit and habitat: Grows as a mounding, clumping, loose mass in average garden soils, but in dry prairies, rocky openings, hill prairies, glades, and sun‑baked slopes it stays compact and tight. Thriving in lean, well‑drained sites, it shrugs off drought, heat, and high sun. In richer soils or partial shade, it will sprawl, open up, and flop around—but not in an unwelcome way; it can be a charming feature as it drapes over boulders, ledges, or container edges. Handles disturbance well, especially fire and light grazing. A mid‑summer “Chelsea Chop” helps control size and habit, delaying bloom slightly but often increasing flower density. This is the last vestige of true color in fall, sometimes blooming right up to Halloween.

Companions: Purple Poppy Mallow (Callirhoe involucrata), Little Bluestem (Schizachyrium scoparium), Prairie Dropseed (Sporobolus heterolepis), Black‑eyed Susan (Rudbeckia hirta), Tall Hairy False Goldenaster (Heterotheca camporum), Showy Goldenrod (Solidago speciosa) or any prairie Goldenrod species, Rattlesnake Master (Eryngium yuccifolium), Foxglove Beardtongue (Penstemon digitalis). 

Ecological Associations: Aromatic Aster blooms very late, drawing in a dense mix of fall pollinators — especially bumble bees like Common Eastern Bumble Bee (Bombus impatiens) and Brown‑belted Bumble Bee (Bombus griseocollis), as well as small native sweat bees (Lasioglossum spp.) and late-season butterflies including Painted Lady (Vanessa cardui) and Pearl Crescent (Phyciodes tharos). The persistent floral display provides crucial nectar during the seasonal downturn when few other natives remain in bloom. Despite the name, deer and rabbits will nibble a bit but far less than most asters. Aromatic Aster hosts several aster‑specialist insects, including Wavy‑Lined Emerald Moth (Synchlora aerata), Silvery Checkerspot (Chlosyne nycteis), and Pearl Crescent (Phyciodes tharos). So, there’s a lot going on in that dense clump of a plant. 

Provenance: Dakota County and/or Greater MN

NH Propagation Technique: Seed and occasionally by root division or stolon.  

Special Powers: A quietly vital food source for the bees, moths, and butterflies who never seem to know when to leave the party. They’re still hanging out in the floral kitchen, nursing a bottle of nectar and debating the existential threats of light pollution while you are cleaning up fallen leaves. It is summer nostalgia incarnate.