American Sweet Flag vs Yellow Hedysarum - TreeTime.ca

American Sweet Flag vs Yellow Hedysarum

Acorus americanus

Hedysarum sulphurescens

CUSTOM GROW

CUSTOM GROW

American Sweet Flag
Yellow Hedysarum

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.

Yellow Hedysarum is a native perennial wildflower recognized for its clusters of pale yellow to creamy-white, pea-like blooms. Flowering from late spring into summer, it adds subtle colour to grasslands, roadsides, and open woods while attracting a variety of pollinators, especially bumblebees.

As a nitrogen-fixing plant, Yellow Hedysarum enriches soils and supports the growth of surrounding vegetation. Its deep taproot and extensive root system make it drought-tolerant and effective at stabilizing soil. Grizzly bears are known to dig up and eat the nutritious taproot. Its resilience and ecological value make it well-suited for restoration, naturalization, pollinator gardens, and erosion control projects.

American Sweet Flag Quick Facts

Yellow Hedysarum Quick Facts

Zone: 3a
Zone: 2b
Height: 0.9 m (3 ft)
Height: 0.5 m (1.5 ft)
Spread: 0.6 m (2.0 ft)
Spread: 0.2 m (0.8 ft)
Light: partial shade, full sun
Light: partial shade, full sun
Moisture: wet
Moisture: dry, normal
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 - low


Foliage: fragrant
Flowers: yellow floral spike
Flowers: creamy yellow, in dense spikes
Bloom time: spring to summer
Bloom time: late 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
Other Names: american sweetflag
Other Names: sulphur hedysarum, sulphur sweet-vetch, yellow sweet-vetch