American sweetflag
Acorus americanus
Last reviewed: August 2026
Acorus americanus is an emergent wetland forb that grows in full sun along marsh edges, pond margins and slow streams, blooming in May and June with a short greenish yellow flower spike.
Toxicity unknown
American sweetflag (Acorus americanus) is not listed by the ASPCA Animal Poison Control Center (opens in new tab) or the other sources we check, so we have no verdict for it either way. Absence from those lists is not a clearance. If your pet shows symptoms after eating any plant, call the ASPCA at (888) 426-4435.
Light
full sun
Water
high
Size
18"–36" H × 12"–24" W
Bloom
May, Jun
Native to
CO, CT, DC, IA and 22 more states
Pollinators
flies, small beetles
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An emergent wetland plant with flat sword-like leaves that release a sweet spicy scent when bruised, and an inconspicuous green flower spike angled off the stem. It spreads by rhizome in shallow standing water and saturated soil.
Growing American sweetflag
Grow American sweetflag in full sun and high water. Mature plants reach 18 to 36 inches tall and spread 12 to 24 inches wide.
Wildlife value
Dense colonies stabilize shorelines and provide cover for wetland birds and amphibians.
Common questions
- What growing conditions does Acorus americanus need?
- It does best in full sun with consistently high moisture, such as marsh edges, pond margins and shallow standing water.
- When does Acorus americanus bloom?
- It typically flowers in May and June, producing a short, fleshy greenish yellow spadix.
- What insects pollinate Acorus americanus?
- Flies and small beetles are the main visitors, attracted to the compact flower spike typical of the arum family.
- Can Acorus americanus tolerate some shade?
- It can handle part sun conditions along stream banks, but it flowers and spreads most vigorously in full sun.
These answers were drafted with an AI model from this plant's data. Verify care details with a local expert.
Native range data from the World Checklist of Vascular Plants (Kew). Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.
If something looks wrong
Common plant problems, and what to check first
These come up on almost any plant. Each guide lists the likely causes in the order they are worth ruling out, with one thing to check before you act on any of them, and links to the source it came from.
- It is dying right after planting
- Leaves turning yellow
- Wilting even though I watered it
- Brown crispy leaf tips
- Bugs on the plant
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