American Sweet Flag vs Knotted Rush - TreeTime.ca

American Sweet Flag vs Knotted Rush

Acorus americanus

Juncus nodosus

CUSTOM GROW

NOT AVAILABLE THIS SEASON - MIGHT RETURN

American Sweet Flag
Knotted Rush

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.

Knotted Rush is a native perennial wetland plant found growing in marshes, swamps, wet meadows, and along shorelines. It spreads by underground rhizomes to form colonies, which can also help stabilize soils and shorelines.

Its upright, slender stems and small clusters of greenish-brown seed heads add structure to wetland plant communities. Knotted Rush is well-suited to wetland conservation, rain gardens, naturalization, and restoration projects. As a cool-season grower, it grows actively during spring and fall, when temperatures are cooler.

American Sweet Flag Quick Facts

Knotted Rush Quick Facts

Zone: 3a
Zone: 1b
Height: 0.9 m (3 ft)
Height: 0.5 m (1.5 ft)
Spread: 0.6 m (2.0 ft)
Spread: 0.2 m (0.5 ft)
Light: partial shade, full sun
Light: full sun
Moisture: wet
Moisture: wet
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


Foliage: fragrant
Flowers: yellow floral spike
Bloom time: spring to summer
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, ON, QC, NS, NB, NL, YT, NT, PE
Other Names: american sweetflag