This adaptable, easy-to-grow ground cover forms mounds of violet-blue flowers in late summer and early fall. The fragrant, yellow-centered flowers are a late-season food source for native bees and butterflies. Crooked stem aster is also known as zigzag aster because its multiple branches feature zig-zagged stems lined with narrow leaves. As an inhabitant of floodplains, moist woodlands, roadsides, and meadows in eastern North America, crooked stem aster thrives in a wide range of average to moist soils and part to full shade in the domestic landscape. It form colonies through horizontal stems that grow at the soil's surface. While it doesn't spread aggressively, the spread can be controlled by thinning out the stems. If the plant become top-heavy and falls open, prune back by no more than half in mid-June. Crooked stem aster often overlaps with purple-stemmed aster (S. puniceus), which has larger purple flower heads.
Native habitats include woodland edges, stream banks, and damp thickets. Use in meadows, native and pollinator gardens, mass plantings, along stream banks, and in borders.
Plant Characteristics:
Grows 1-4’ tall.
Prefers full or part shade.
Grows in average to moist, loamy soils that are neutral to slightly acidic and also in clay and sandy soils. Tolerates occasional flooding.
Flowers are less than an inch wide and have 20-30 strap-shaped petals and tubular, yellow disk florets. Floral bracts are narrow and translucent. Flowers give way to flat, brown, hairy achenes.
Simple, alternate, leaves with toothed margins are ½-3” long. The leaves become narrowed in the lower third of the stem but then expand at the base to clasp the stem.
Reproductive System: Reproduces both by seed and asexually through stolons (horizontal stems that produce new plants from buds). It's self-incompatible and needs at least two genetically different individuals to produce viable seed.
least two genetically different individuals to produce seed.
Wildlife Value:
Host plant for 112 species of Lepidoptera larvae, including silvery checkerspot butterfly and specialists aster flowerhead caterpillar, aster-head phaneta, Essex phaneta, and Hoffman's cochlid moth. Asters supports the following specialized bees: Andrena (Callandrena s.l.) asteris, Andrena (Callandrena s.l.) asteroides, Andrena (Cnemidandrena) hirticincta, Andrena (Cnemidandrena) nubecula, Andrena (Callandrena s.l.) placata, Andrena (Callandrena s.l.) simplex, and Colletes simulans. Wild turkeys, upland game birds, and deer occasionally browse the seeds and foliage.
Medicinal, Edible, and Other Uses:
A tea made from the roots has been used to treat fevers in infants and colds and kidney problems in adults.
Resources:
National Wildlife Federation
https://nativeplantfinder.nwf.org/Plants/3195
North Carolina Extension
https://plants.ces.ncsu.edu/plants/symphyotrichum-prenanthoides/
Penn State Extension
https://extension.psu.edu/aster-as-a-keystone-species
USDA
https://plants.usda.gov/DocumentLibrary/factsheet/pdf/fs_sypr6.pdf
