American Sweet Flag vs Showy Aster - TreeTime.ca

American Sweet Flag vs Showy Aster

Acorus americanus

Eurybia conspicua

CUSTOM GROW

CUSTOM GROW

American Sweet Flag
Showy Aster

American Sweet Flag is a native perennial wetland plant found along shorelines, streams, wet meadows, and marshes. Its extensive rhizome system allows it to spread and stabilise soil, helping maintain the edges of ponds and streams. This dense growth provides cover for small animals and supports overall wetland biodiversity, while the rhizomes and seeds serve as food for small mammals and waterfowl. Cold-hardy and resilient, it is well-suited for ecological restoration, riparian plantings, erosion control, and naturalization projects.

The plant grows in dense clumps with tall, sword-shaped leaves that release a citrus-like scent when bruised. The rhizomes are aromatic, with a spicy, cinnamon-like fragrance that has been used in perfumery and flavouring. In early summer, American Sweet Flag produces a distinctive floral spike (spadix), adding visual interest to wetland plantings.

Showy Aster is a native perennial wildflower recognized for its tall stems topped with clusters of light purple blooms. Blooming from late summer into autumn, it provides an important late-season source of nectar and pollen for pollinators. It also produces seeds that are eaten by birds, extending its value to wildlife beyond the flowering season.

Drought tolerant once established, Showy Aster grows well in urban, rural, and disturbed sites. With its mix of ecological value and ornamental appeal, it is ideal for pollinator gardens, naturalization projects, and ecological restoration.

American Sweet Flag Quick Facts

Showy Aster Quick Facts

Zone: 3a
Zone: 2b
Height: 0.9 m (3 ft)
Height: 0.6 m (2.0 ft)
Spread: 0.6 m (2.0 ft)
Spread: 0.5 m (1.5 ft)
Light: partial shade, full sun
Light: partial shade, full sun
Moisture: wet
Moisture: any
Growth rate: fast
Growth rate: fast
Life span: short
Life span: short
Growth form: upright, colony-forming
Growth form: upright, colony-forming
Spreading: rhizomes - high
Spreading: rhizomes - medium, seeds - medium


Foliage: fragrant
Flowers: yellow floral spike
Flowers: purple-blue, with yellow centers
Bloom time: spring to summer
Bloom time: late summer to early fall
Hybrid: no
Hybrid: no
Catkins: no
Catkins: no


Native to: AB, BC, SK, MB, ON, QC, NS, NB, NL, NT, PE
Native to: AB, BC, SK, MB
Other Names: american sweetflag
Other Names: western showy aster