Known as tall ironweed or giant ironweed, perennial Vernonia gigantea is big, purple, and native. A member of the aster family, ironweed can grow seven feet and taller in a season before finally blooming late July to September.
Ironweed in the landscape
Being honest, I have whacked ironweed back harshly on more than one occasion, a half-hearted effort at getting rid of it. It’s so big and a bit coarse. Surrounded by more genteel plants one might think the last thing needed is a great big purple plant. Thankfully ironweed bears its name for a reason (it is tough), and I am unfailingly grateful for it when September arrives.
The bees are grateful as well. Ironweed is like a busy rest stop on one of America’s interstates, the bees providing a constant stream of traffic. You will also see butterflies make the occasional stop to harvest nectar. As resources available to various species of birds, bees, and butterflies begin to dwindle, the plants that bloom on the edges of the seasons are often our most valuable.
You can grow Vernonia in moist soils…it likes swamps and stream sides. Average moisture is fine as well…seasonal rain is more than enough to keep it happy. Full sun to partial shade is recommended. Ironweed has strap-like leaves not dissimilar to butterfly weed, although the leaves are much larger (6″-12″ long).
Vernonia gigantea is hardy, found across the entire eastern half of North America from Canada to Florida. Deer don’t seem to bother it much, and ironweed is largely resistant to disease.
The USDA Forest Service has a really great article on giant ironweed – with some nice images. Vernonia gigantea can be a little hard to find commercially, so try Goodness Grows (to maintain credibility we do not recommend companies for personal gain or compensation – there is nothing in it for us other than helping out our fellows).