Want a plant that will stand up for you in your garden? Think about growing ironweed. A member of the aster family, this attractive Illinois native comes in many varieties, all of which share some common characteristics. Named for its sturdy, upright stem, ironweed in the wild inhabits meadows, prairies, the edges of woodlands, areas beside rivers and swamps, and disturbed ground in overgrazed pastures or alongside railroad tracks. The variety most common in northern Illinois is, appropriately enough, called common ironweed.
Ironweed’s single central stem is stout and stiff, and covered with fine hairs. It branches only near the top, where striking bright purple flowers appear in late summer to early fall. The showy blooms are attractive not only to humans but to many types of pollinators, among them butterflies and bees. Ironweeds serve as host plants for several types of butterfly larvae.
While ironweed prefers full sun and moist soil, it tolerates a wide range of conditions; so while it can be somewhat drought resistant, some of its varieties thrive in rain gardens. It is not generally fussy about soil type; loamy, clay, or sandy soils are fine. Average plant height is 3 to 6 feet, though some varieties, like giant ironweed, can reach 10 feet. Its height makes ironweed it a good backdrop for your lower-to-the-ground plantings. Because its stems are strong, it can lend physical support to surrounding plants. With its dense root system, it’s good at keeping soil on sloping ground from eroding. If you want a shorter plant, cutting the stem back in the spring will encourage ironweed to keep its height in check. Given ideal conditions, ironweed tends to spread aggressively, so you might not want it in smaller, controlled plantings. Otherwise, trimming off flower heads before they form seed helps keep it where you want it.
According to one source, the stem of common ironweed was used as a ceremonial wand by the Yuchi group of Native Americans. The root of the ironweed has reportedly been used to make medicinal powders to stimulate appetite, promote digestion, and treat “female complaints,” fever, and even syphilis. A decoction of the leaves was used to soothe sore throats.
Could sturdy and colorful ironweed, attractive to pollinators and people alike, become a favorite perennial in your garden?
Written by Monica Buckley
Common ironweed: Vernonia fasiculata
Giant ironweed: Vernonia gigantea