Virginia ecotype
Duration: PerennialHabit: Upright, sometimes arching; often forms loose colonies via rhizomes and reseeding
Size: 3 to 6 feet tall; 2 to 4 feet wide; may need support in bloom
Flowering Time: August to October
Bloom Color: Lavender to violet with yellow centers (turning reddish after pollination)
Habitat: Wet meadows, swamps, marsh edges, ditches, and moist woods
Moisture: Moist to wet; prefers consistently damp or seasonally saturated soil
Light: Full sun to part shade; best show in full sun
Soils: Loamy or clay soils, sometimes peaty; tolerant of poorly drained conditions
Uses: Wetland restoration, native plant gardens, pond and stream edges, rain gardens, pollinator habitats
Symphyotrichum puniceum (Swamp aster)
Swamp Aster, sometimes also known as Red-stemmed or Purple-stemmed Aster, is a tall, moisture-loving perennial aster found in wetlands and other saturated soils. It’s named for its often reddish or purplish-tinged stems, and its tendency to occur in coastal, seasonally flooded or consistently wet regions, which helps to differentiate it from many other asters.
Swamp aster blooms in late summer and fall, producing loose clusters of violet to light lavender flowers with yellow centers. As with many asters, upon successful pollination of a single flower the center gradually turns redish purple. Asters support a wide array of pollinators, especially native bees, including many specialist bees, and late-flying butterflies. Its fluffy wind-dispersed seeds are eaten by songbirds such as sparrows and finches. It is also a host plant for several moths and butterflies, including the Pearl Crescent (Phyciodes tharos).
Unlike other asters, S. puniceum spreads moderately and doesn’t dominate wetland plant communities, making it a good companion in diverse native assemblages. It can tolerate seasonal standing water for short periods and part sun shaded areas, but performs best in consistently moist, sunlit areas. This species seems to appreciate being planted with other tall plants to lean on, as the profuse flowers weigh the stems down. It is also happy to sprawl and form a bushy appearance.
Companion plants to consider include: Packera aurea (as a low groundcover), Clematis virginiana (vining), Lobelia cardinalis, Purple-headed sneezeweed, and for tall support Common sneezeweed, Culver's root, Swamp Rose (Rosa palustris), and Joe-pye weed.
Synonymous with Symphyotrichum puniceum var. puniceum