Vernonia lettermannii (threadleaf ironweed) flowers

Vernonia lettermannii | threadleaf ironweed

This plant will not be available in 2026, however, propagation is planned/underway. Please sign up for the waitlist below to receive updates on availability in future years.

Ironweed are tall US natives that look quite similar to each other. All bloom late in the season; purple flowers are much loved by pollinators, especially butterflies.

Threadleaf ironweed is a compact clump-forming perennial with finely textured narrow leaves. Picture a small, rounded Amsonia hubrichtii with purple fall flowers. It tolerates hot, dry, rocky soil just as well as moist soil.

Zones: 4 to 9
Family: Asteraceae
Type: Perennial
Height: 24 to 36 in.
Spread: 24 to 36 in.
Exposure: Full Sun
Soil Conditions: Dry, average, moist
Bloom Time: August to September
Bloom Color: bright purple-violet
Native Range: Arkansas and Oklahoma

Special Characteristics

Pollinator favorite
Little to no care required (once established)
Architectural

image credits

Image 1 (blooms) Eric Hunt, CC BY-SA 4.0, via Wikimedia Commons
Image 2 (closeup) Krzysztof Ziarnek, Kenraiz, CC BY-SA 4.0, via Wikimedia Commons
Image 3 (form) Daderot, Public domain, via Wikimedia Commons