Roughstem rosinweed
Silphium radula
Last reviewed: August 2026
Silphium radula, roughstem rosinweed, is a sun-loving prairie forb that produces yellow flowers from June through September and grows well in dry glades, rocky open woods, and prairie remnants of the south-central United States.
Toxicity unknown
Roughstem rosinweed (Silphium radula) 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
36"–72" H × 24"–36" W
Bloom
Jun, Jul, Aug, Sep
Native to
AR, KS, LA, MO and 3 more states
Pollinators
bees, butterflies, beetles
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A tall, upright perennial forb with rough, sandpaper-textured leaves and bright yellow, sunflower-like flower heads held on branching stems in summer. Develops a deep root system that supports strong drought tolerance once established.
Growing Roughstem rosinweed
Grow Roughstem rosinweed in full sun and medium water. Mature plants reach 36 to 72 inches tall and spread 24 to 36 inches wide. Expect moderate maintenance to keep it looking intentional in a front yard.
In an HOA neighborhood
Roughstem rosinweed is an HOA-friendly choice in the right placement. Maintenance level: moderate. Tidiness: 2 out of 5.
Works well in: mid zone, backyard only.
- Tall coarse growth habit may read as weedy to HOA reviewers if not maintained in a defined bed
Wildlife value
Host plant for Silvery checkerspot butterfly.
Flowers attract bees, butterflies, and beetles; the plant serves as a larval host for the silvery checkerspot butterfly, and seed heads feed birds in fall and winter.
Common questions
- When does roughstem rosinweed bloom?
- Roughstem rosinweed typically flowers from June through September, producing yellow, sunflower-like blooms on tall, rough-textured stems.
- What kind of light and water does this plant need?
- It grows best in full sun with medium moisture, but established plants tolerate part sun and drier, well-drained soils once rooted.
- What pollinators visit roughstem rosinweed?
- Bees, butterflies, and beetles regularly visit the flowers for nectar and pollen through the summer bloom period.
- What habitat suits roughstem rosinweed best?
- It does well in open prairies, glades, and dry to medium upland sites with good drainage and full sun exposure.
- Does roughstem rosinweed die back in winter?
- Yes, it is a herbaceous perennial forb that dies back to the ground each year and regrows from its rootstock in spring.
- Is Roughstem rosinweed HOA-friendly?
- Roughstem rosinweed 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.
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