1282 Vernonia noveboracensisCommon Names: ironweed,New York ironweed Family: Asteraceae (daisy Family)
Ironweed is an herbaceous perennial that gets up to 6 ft (2 m) tall during its growing season before hibernating through the winter. The plant is upright and distinctly columnar, with branching stems that extend a couple feet (60 cm) out. Leaves are lance shaped, about 8 in (20 cm) long and less than an inch (2.5 cm) wide, with long tapered points. They are borne alternately along the stems and lack petioles. The leaves are sandpapery on top and may or may not be toothed on the edges. The inflorescence is a terminal flat topped cyme consisting of tubular purple or (rarely) white florets in heads about a half inch (1.3 cm) across. There are some 20-40 tubular disk florets in each head, and there are no ray flowers at all. The whole inflorescence is about 6-8 in (15-20 cm) across, and there is one at the terminus of each branch.
Ironweed reminds one of Joe Pye weed (Eupatorium fistulosum), but a little smaller and with alternate leaves.
Vernonia noveboracensis is native to the eastern United States, mainly east of the Appalachians, from Massachusetts to northern Florida. It occurs in damp thickets, meadows, roadsides, along streams, and in moist bottomland fields. Ironweed is cultivated more by gardeners in Europe than those in its native land.
If you cut the plant back by one-half or more when it is 2-3 ft (60-90 cm) tall, it will branch out and make more flowering stems. If you deadhead spent flowerheads as soon as they finish blooming, more will develop. Light: Grow ironweed in full sun for best results. They tolerate partial shade but may not bloom as profusely. Moisture: Ironweed does best in a moist soil but tolerates drier situations. It likes a slightly acidic soil. Hardiness: USDA Zones 5 - 9 . Propagation: Divide the root mass to make new plants. Seeds should be sown in containers in spring, or planted out when ripe in fall.
Ironweed is grown in mixed borders and flower beds, and is a welcome addition to the naturalistic wild flower garden. It has been used effectively in rain gardens since it tolerates very soggy soils and also dry soils. Ironweed is easy to grow and may self-seed under ideal conditions. Ironweed gets pretty tall and is a rather coarse perennial that might be at its best in the back of the border or bed. Cutting the stem back early in the growing season will result in a shorter, bushier plant. The deep reddish purple flowers bloom in summer and last well into autumn when many other garden flowers are petering out. A planting of ironweed and Goldenrod (Solidago sempervirens, for example) brings bright contrasting colors, butterflies and joy to the fall garden.
Butterflies nectar at the tubular florets and birds dine on the seeds. Native Americans made a tea from ironweed leaves to treat various maladies including childbirth pain. A tea from the roots was used to treat stomach ulcers and bleeding.
There are as many as 1000 species of Vernonia. Most are tropical and most are indigenous to South America, but a few occur in Africa, Asia, Australia or North America. Most species are trees or shrubs, but those from northern climes are perennials or annuals. There are around 17 species native to the United States. Only a few species of Vernonia have been brought into cultivation.
Steve Christman 3/6/17