Arrowleaf Aster (Symphyotruchum Urophyllum)

Local Name: Arrowleaf Aster

Botanical Name: Symphyotrichum urophyllum

Family: Asteraceae

Native Status: Dakota County Native

Landscape Archetype: Savanna, Edgeland, Woodland

Life Cycle: Perennial

Sun Exposure: Full Sun, Part Sun, Shad

Soil Moisture: Mesic, Dry 

Soil Type: Loam, Silt, Clay, Sand, Gravel 

Height & Width Range: Height: Waist 24"–36" Width: 12"–18"

Bloom Color: White 

Morphology Notes: A slender, upright, forming loose vase shape. Basal leaves are distinctive, broad at the base and narrowing into a drawn‑out point. Upper leaves get narrower and clasp the wiry, lightly hairy stems. Flower sprays are light and open, holding dozens of small white daisy rays around yellow center disks that flush with wine color as they age. Root system is fibrous and shallow. 

Fruits and Seeds: Seeds are small tan‑brown achenes with faint ribs and a soft white pappus. As the seedheads mature, they take on a pale, tufted look and move easily with a breeze. They persist long enough to add light fall texture before dispersal. The seeds and stems often last well into winter adding a beautiful brown wiry texture to winter gardens.  

Habit and habitat: A species found in oak savannas, open woodlands, bright trail edges, and thin slopes where prairie transitions into woodland. Thrives in well‑drained upland soils with moving light. In deeper shade the plant stretches. In brighter edges it stays tight, erect and produces abundant blooms. Will fade away in crowded landscapes. Not as robust or aggressive as other white flowering asters like Ontario Aster. Responds well to pruning to control the height. 

Companions: Sprengel’s Sedge (Carex sprengelii), Canada Wild Rye (Elymus canadensis), Red Baneberry (Actaea rubra), Zigzag Goldenrod (Solidago flexicaulis), Blue Wood Aster (Symphyotrichum cordifolium), Woodland Sunflower (Helianthus strumosus), Large‑flowered Bellwort (Uvularia grandiflora), Wild Geranium (Geranium maculatum), Smooth Solomon’s Seal (Polygonatum biflorum)

Ecological Associations: Arrowleaf Aster supports a wide mix of late‑season insects including Sweat Bees (Lasioglossum zephyrus), Mining Bees (Andrena species), Bumble Bees (Bombus impatiens), Syrphid flies including Margined Hover Fly (Toxomerus marginatus) and Soldier Beetle (Chauliognathus pensylvanicus) who forage on the flowers. Several moths’ nectar at the flowers during dusk, including Wavy‑lined Emerald (Synchlora aerata) and other aster‑associated micromoths. Leaf‑mining larvae tied to woodland Symphyotrichum species feed on the foliage. Leafhoppers, planthoppers, and juvenile Orthoptera shelter in the plant’s lower structure, and its dried seedheads create small, protected spaces used by minute spiders, leafhoppers, planthoppers, tiny beetles, psyllids, thrips, lacewing larvae, and other micro‑arthropods as overwintering refuges. Almost all mammals will eat this plant, but it has evolved with this and will regrow quickly. 

Provenance: Dakota County and Greater MN 

NH Propagation Technique: Seed

Special Powers: Arrowleaf Aster is a sleeper hit. While the idea of white asters might not seem very exciting faced with goldenrods and purple asters, but the timing of this plant’s bloom has a certain choreography with the dipping sun that will surprise you. Many trees won’t have dropped their leaves when Arrowleaf aster is blooming so those white flowers will pop out among the shady edges of woodland gardens. A highly variable species that can also take a fair amount of direct sun. Here at NH HQ we have this plant right by our front door and it’s a cheery bloom to admire in sweater weather with a cup of coffee.