Fall has arrived in South Carolina! Native fall-blooming wildflowers, with their flower colors of intense purple, yellow, orange, and white hues, brighten up the autumn landscape. One of my favorites is Ironweed (Vernonia species), with its vivid, deep purple flowers that bloom in late summer to early fall.
Ironweed (Vernonia species) has vivid, purple flowers that bloom in the late summer to early fall.
Barbara H. Smith, ©2023 HGIC, Clemson University
It’s in the Asteraceae family, and there are a number of species native to the Southeast. Ironweed gets its common name due to the rusty-colored faded flowers and achenes (seeds), giving them the color of rusted iron. The coarse, elongated, alternately arranged leaves are dark green on the upper side and a paler green underneath.
Ironweed gets its common name from the rusty color of the faded flowers and the seed heads.
Barbara H. Smith, ©2023 HGIC, Clemson University
Plant ironweed in moist, organically rich soil in full sun to partial shade. Depending on the species, ironweed can reach 3 to 12 feet tall with a spread of 3 to 6 feet. To maintain a shorter height, you can prune the plant back by one-third in the early summer. Deadheading the faded flowers will also promote a longer bloom cycle.
To prevent reseeding, remove the seeds before they mature. It’s a great plant to add to the back of a perennial border or pollinator garden. Ironweed has a strong, erect stem, which does not require staking.
Ironweed is a host plant for American Lady Butterflies and Crossline Skippers and a nectar source for Fiery Skippers, Swallowtails, and Monarchs. Other beneficial insects, such as bees, beetles, flies, and moths, depend on ironweed for food and shelter. Spiders, robber flies, assassin bugs, and other predatory insects are also present and hunt the insects that feed on the flower nectar and pollen. Ironweed is a supermarket for insects, supporting an entire food chain for prey and predators.
It also doesn’t have major disease or insect issues. The foliage tastes bitter, so deer and other animals tend to leave it alone.
Plant ironweed in a border with other fall-flowering perennials. It contrasts well with other fall flowering perennials, such as black-eyed Susan, goldenrod, swamp sunflower, salvias, and Joe-Pye weed, to name a few.
Ironweed’s deep purple flowers contrast well with the bright yellow black-eyed Susan blooms.
Barbara H. Smith, ©2023 HGIC, Clemson University
