Vernonia lettermannii 'Iron Butterfly' Threadleaf Ironweed



Vernonia lettermannii 'Iron Butterfly' forms vigorous clumps of narrow stems with fine, feathery foliage that are topped by clusters of fluffy, true purple blooms at stem ends in late summer and early fall. Vernonia lettermannii 'Iron Butterfly' foliage resembles that of Amsonia hubrichtii. The blooms are loved by butterflies and is very nice planted with grasses and other late summer blooming perennials.

Vernonia lettermannii, also known as Threadleaf Ironweed, is native to Arkansas and Oklahoma. It is typically found on gravel river bars and nearby rocky outcrops.

Vernonia lettermannii 'Iron Butterfly' prefers full sun and well-drained soil, but is very tolerant of rough, sandy, infertile, dry soils and hot, dry locations. However, it can withstand occasional flooding. Rust resistant.


  • Common Names: Ironweed
  • Zones: 4-9
  • Light Requirements: Full Sun to Light Shade
  • Soil Preference: Prefers moist, well-drained soil
  • Height at Maturity: 30-36
  • Width at Maturity: 36
  • Bloom Color: Purple
  • Bloom Time: Late summer to early fall

Special Features

  • Attracts: Butterflies. Hummingbirds. Pollinators.
  • Tolerates: Clay Soil. Drought.
  • Other Features:

Care and Growing Tips

Check out our blog for more gardening tips!

Shipping Info

 Spring 2023 shipping schedule:

Zones 9, 10: Starting Mon. March 20th
Zone 8: Starting Mon. March 27th
Zone 7: Starting Mon. April 3rd
Zone 6: Starting Mon. April 17th
Zone 5: Starting Mon. May 1st
Zones 2, 3, 4: Starting Mon. May 8th

If you'd like to receive your plants now, you can request it in the 'shipping requests' box on the order or email us. (Please note that we will not ship dormant plants, and we do not offer any sort of guarantee for plants overwintering.)

- - - - - - - - - - - - - - 

We ship via UPS & USPS (the Post Office), and their ship rates are automatically generated through our site. We do not profit on shipping costs. We are working with these providers to get our customers the best rates possible.

All ship times are subject to change if extreme weather conditions are present here at the nursery or at the shipping destination.

Please note: Depending on the time of year, the foliage of the plants may be trimmed to fit into our shipping boxes. This could delay the flowering of the plant, but many perennials actually benefit from being cut back.

We are currently not able to ship to Puerto Rico, Hawaii, and outside of the US.