The ironweed, or common ironweed, is a robust, native, herbaceous perennial that is found throughout the eastern half of North America. It is a member of the Aster family and, therefore, has a flower head similar to the sunflower. The disk flowers are purple although much smaller than sunflower and the ray flowers are absent.
This plant can achieve heights of 6 - 7 feet with a diameter of 2 feet. It produces a dark purple flower that has white hair-like threads in the interior.
This species prefers a rich, moist slightly acidic soil with at least 4 – 6 hours of full sun each day. The ironweed can accommodate long periods of drought. It is by no means a “weed” but it can be aggressive when grown under optimal conditions.
Ironweed is a good accent plant perhaps used as an inflection point between two garden areas. It does well with the strong yellow blooms of goldenrod, cup plant and others that bloom during the same season – from mid-summer until the time of the first frost.
The seeds of ironweed are extremely small and with their downy nature are wind-distributed for propagation.
Ironweed is a host species for the American Painted Lady butterfly.
This species is favored by many pollinator species including butterflies, bees, and birds.
The ironweed is also deer- and rabbit-resistant.
There are no reported insect or disease problems for this species although it can be susceptible to powdery mildew in areas with poor to no air circulation.
It is thought that the common name of his species comes from the stem or this plant that is difficult to cut or otherwise manipulate.
In spite of its common name this plant is a rather unexceptional ornamental in the garden.
About the Author
Charlie Belin is a retired professor and biological oceanographer. He taught five courses in the University of Georgia system for many years from his home base in Savannah, Georgia.
Charlie loves hiking at Reflection Riding, teaching children about the ecology of the area, and interacting with the Reflection Riding staff. They are GREAT!