American Senna
Senna marilandica
Last reviewed: August 2026
Senna marilandica is a native perennial wildflower found across eastern and central United States. It produces bright yellow flower clusters from June through August and serves as an important pollinator plant.
Toxicity unknown
American Senna (Senna marilandica) 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.
The USDA PLANTS Database (opens in new tab) does not flag American Senna as toxic to livestock.
Light
full sun
Water
medium
Size
24"–48" H × 24"–36" W
Bloom
Jun, Jul, Aug
Native to
AL, AR, CT, FL and 24 more states
Pollinators
bees, butterflies
Before you buy
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Wild senna produces clusters of bright yellow flowers from June through August on upright stems with compound leaves. This native perennial forms a rounded clump and develops attractive seed pods in fall. The plant has a clean, structured appearance that works well in cultivated gardens.
Growing American Senna
Grow American Senna in full sun and medium water. Mature plants reach 24 to 48 inches tall and spread 24 to 36 inches wide. Expect low maintenance to keep it looking intentional in a front yard.
In an HOA neighborhood
American Senna is an HOA-friendly choice. Maintenance level: low. Tidiness: 4 out of 5.
Works well in: front yard, foundation, street edge, mid zone.
- Seed pods may look untidy if not removed
Wildlife value
Host plant for cloudless sulphur, little yellow butterfly.
The flowers attract native bees and butterflies, while the foliage serves as a host plant for some butterfly species. Seeds provide food for birds in fall and winter.
Common questions
- When does American Senna bloom?
- American Senna blooms from June through August, producing clusters of bright yellow flowers that attract bees and butterflies.
- Where is Senna marilandica native?
- American Senna is native to much of the eastern and central United States, from Massachusetts south to Florida and west to California, including the Great Plains and southeastern states.
- What pollinators visit American Senna?
- American Senna attracts various bees and butterflies with its bright yellow summer flowers, making it valuable for pollinator gardens.
- What growing conditions does Senna marilandica prefer?
- American Senna grows best in full sun but tolerates partial sun, and adapts to a wide range of moisture conditions from wet to dry soils.
- Is American Senna toxic to livestock?
- The USDA PLANTS Database does not flag American Senna as toxic to livestock.
- Is American Senna HOA-friendly?
- American Senna is generally an HOA-friendly choice in the right placement, with low maintenance.
These answers were drafted with an AI model from this plant's data. Verify care details with a local expert.
Native range data from vouchered herbarium specimen records and regional native plant society lists. Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.
Ready to grow American Senna? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.
Not sure where to start? Take the 2-minute yard quiz