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

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Shipping Info


All orders placed now will be held until late August/early September when our fall shipping season begins. We stop shipping plants every summer due to the high temperatures. We appreciate your patience!

If you'd like to receive your order before our fall season, you can leave a note for us on the Cart page before you reach checkout. Please note that we will have to wait for a window of cooler temperatures to ship. We cannot promise any particular shipping date during the summer. 


plants shipped to your door

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We ship via UPS or 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.