Thinleaf Cottonsedge
Eriophorum viridicarinatum
Last reviewed: June 2026
Light
part sun
Water
high
Size
8"–24" H × 6"–12" W
Bloom
May, Jun, Jul
Native to
CO, CT, IA, ID and 16 more states
Pollinators
bees, flies
Thinleaf cottonsedge is a native wetland perennial that forms small clumps of narrow, grass-like foliage. It produces distinctive white, fluffy seed heads from late spring through summer that give it its common name. This plant thrives in consistently moist to wet soils and partial sun conditions.
In an HOA neighborhood
Thinleaf Cottonsedge takes more care to keep looking intentional in a front yard. Maintenance level: moderate. Consider it for backyard or mid-zone beds rather than the street edge.
Works well in: backyard only.
- Looks wild and unmanicured even when healthy
- Requires constantly wet soil that may be impractical in typical landscapes
- Fluffy seed heads can appear messy to some
Wildlife value
The flowers attract bees and flies during its May through July bloom period. The fluffy seed heads provide material for bird nesting and the plant offers habitat for wetland-associated wildlife.
Common questions
- How much sun does Thinleaf Cottonsedge need?
- Thinleaf Cottonsedge grows best in part sun conditions.
- When does Thinleaf Cottonsedge bloom?
- Thinleaf Cottonsedge blooms in May, June, and July.
- Where is Thinleaf Cottonsedge native?
- Thinleaf Cottonsedge (Eriophorum viridicarinatum) is native to CO, CT, IA, ID and 16 more states, per the USDA PLANTS Database and regional native plant society lists.
- What pollinators does Thinleaf Cottonsedge attract?
- Thinleaf Cottonsedge draws bees and flies.
- Is Thinleaf Cottonsedge HOA-friendly?
- Thinleaf Cottonsedge takes more care to look intentional in a front yard. Consider it for backyard or mid-zone beds rather than the street edge.
Native range data from the USDA PLANTS Database and regional native plant society lists. Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.
Ready to grow Thinleaf Cottonsedge? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.
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