American Sweet Flag vs Marsh Cinquefoil - TreeTime.ca

American Sweet Flag vs Marsh Cinquefoil

Acorus americanus

Comarum palustre

CUSTOM GROW

CUSTOM GROW

American Sweet Flag
Marsh Cinquefoil

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.

Marsh Cinquefoil is a native perennial wetland plant with striking reddish-purple, star-shaped flowers. They bloom in early to mid-summer, providing nectar for bees, flies, and other pollinators. Beyond its summer blooms, the foliage turns red in autumn, adding seasonal interest to wetland landscapes.

Common in wetlands, pond margins, and wet meadows, Marsh Cinquefoil spreads by rhizomes to form colonies or patches that contribute to shoreline stabilization. It thrives in nutrient-poor, saturated soils where many other plants struggle, making it valuable in challenging wetland conditions. With its ecological function and ornamental appeal, it is well-suited for wetland plantings, ecological restoration, and naturalized projects.

American Sweet Flag Quick Facts

Marsh Cinquefoil 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: 0.3 m (1.0 ft)
Light: partial shade, full sun
Light: partial shade, 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: ascending to upright
Spreading: rhizomes - high
Spreading: seeds - medium, rhizomes - medium


Foliage: fragrant
Flowers: yellow floral spike
Flowers: dark red/maroon, star-shaped
Bloom time: spring to summer
Bloom time: 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, NU, PE
Other Names: american sweetflag
Other Names: marsh five fingers, purple cinquefoil, purple marshlocks