Rosebay Willowherb
Chamaenerion angustifolium
Last reviewed: July 2026
Chamaenerion angustifolium (Rosebay Willowherb) is a native perennial forb that blooms from June through September with tall spikes of pink flowers. This adaptable plant thrives in various light conditions and attracts bees, butterflies, and moths.
Light
part shade
Water
medium
Size
24"–60" H × 12"–24" W
Bloom
Jun, Jul, Aug, Sep
Native to
AL, AR, CA, CO and 39 more states
Pollinators
bees, butterflies, moths
Deer
Resistant (per Prairie Moon Nursery)
Browse plants for this ecoregion
Rosebay willowherb is a tall perennial wildflower that produces striking spikes of bright pink-purple flowers from summer through early fall. This native plant forms upright colonies and thrives in partial shade with moderate moisture, making it suitable for naturalized areas and woodland edges.
Growing Rosebay Willowherb
Grow Rosebay Willowherb in part shade and medium water. Mature plants reach 24 to 60 inches tall and spread 12 to 24 inches wide. Expect low maintenance to keep it looking intentional in a front yard.
In an HOA neighborhood
Rosebay Willowherb takes more care to keep looking intentional in a front yard. Maintenance level: low. Consider it for backyard or mid-zone beds rather than the street edge.
Works well in: backyard only.
- Spreads aggressively and can look weedy
- Very tall growth may appear uncontrolled
- Common name includes 'weed' which raises HOA concerns
Wildlife value
Host plant for white ermine moth.
The long blooming period provides nectar for bees, butterflies, and moths throughout the growing season. Seeds also attract birds in late fall.
Common questions
- When does Rosebay Willowherb bloom?
- Chamaenerion angustifolium typically blooms from June through September, producing tall spikes of pink flowers that attract various pollinators.
- What pollinators visit Rosebay Willowherb?
- This native plant attracts bees, butterflies, and moths with its nectar-rich flowers during its extended bloom period.
- What growing conditions does Chamaenerion angustifolium prefer?
- Rosebay Willowherb is adaptable to full sun through partial shade and prefers medium to high moisture conditions, making it suitable for various garden settings.
- Is Rosebay Willowherb HOA-friendly?
- Rosebay Willowherb 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 Rosebay Willowherb? 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