Thin-leaf Sunflower
Helianthus decapetalus
Last reviewed: August 2026
Helianthus decapetalus (Thin-leaf Sunflower) is a native perennial wildflower found throughout eastern and central United States. This yellow-flowered sunflower blooms from July through September and attracts bees, butterflies, and beetles.
Toxicity unknown
Thin-leaf Sunflower (Helianthus decapetalus) 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
medium
Size
24"–60" H × 12"–24" W
Bloom
Jul, Aug, Sep
Native to
AL, AR, CT, DE and 26 more states
Pollinators
bees, butterflies, beetles
Before you buy
Your city may pay you to plant this
Cities and water utilities offer rebates for replacing lawn with native and water-wise plants. We track 445 programs across 44 states, each with a link to the provider and the date we last checked it.
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Thin-leaf sunflower is a native perennial that produces cheerful yellow daisy-like flowers from July through September. This clumping sunflower reaches 2-5 feet tall and spreads moderately, making it suitable for naturalized areas and pollinator gardens.
Growing Thin-leaf Sunflower
Grow Thin-leaf Sunflower in full sun and medium water. Mature plants reach 24 to 60 inches tall and spread 12 to 24 inches wide. Expect moderate maintenance to keep it looking intentional in a front yard.
In an HOA neighborhood
Thin-leaf Sunflower is an HOA-friendly choice in the right placement. Maintenance level: moderate. Tidiness: 2 out of 5.
Works well in: mid zone, backyard only.
- Can look weedy when dormant in winter
- May appear too informal for formal landscapes
- Height and spread could seem uncontrolled to some HOAs
Wildlife value
Host plant for silvery checkerspot butterfly.
The bright yellow blooms attract bees, butterflies, and beetles throughout the summer and fall. Seeds provide food for birds, particularly goldfinches and other songbirds.
Common questions
- When does Thin-leaf Sunflower bloom?
- Helianthus decapetalus blooms from July through September, producing bright yellow flower heads during the late summer months.
- What pollinators visit Thin-leaf Sunflower?
- This native sunflower attracts a variety of pollinators including bees, butterflies, and beetles. The open flower structure provides easy access to nectar and pollen.
- Where is Helianthus decapetalus native?
- Thin-leaf Sunflower is native to much of the eastern and central United States, from Maine south to Georgia and west to Iowa and Oklahoma.
- What growing conditions does Thin-leaf Sunflower prefer?
- This adaptable perennial grows best in full sun to partial sun with medium moisture levels, though it can tolerate a range of water conditions from wet to dry soils.
- Is Thin-leaf Sunflower HOA-friendly?
- Thin-leaf Sunflower is generally an HOA-friendly choice in the right placement, with moderate 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 the World Checklist of Vascular Plants (Kew). Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.
Ready to grow Thin-leaf Sunflower? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.
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