Illinois Native Plant Guide - Common Iron Weed - Pages 156-157
Illinois Native Plant Guide
Common Iron Weed Vernonia fasciculata
Preferred Water Depth and Inundation Tolerance
Wet prairie, sedge meadow, and shallow marsh species. Species tolerates
inundation of 2-3 inches early in the season.
Serves as a nectar source for insects.
Stoloniferous habit stabilizes upper shorelines and upland slope buffers.
Availability, Establishment, and Maintenance
The germination percentage for Common Iron Weed is very low which may be
because it produces many nonviable seeds. Germination rates can be increased by
sowing stored seed in a seed frame outdoors in June. If soil temperature is
consistently warm, germination and seedling growth are very rapid.
Transplant seedlings to individual containers when a rosette-like cluster of 3
to 4 four leaves develop and then move plants to the site when roots fill
For cuttings, take 4-6 inch stem cuttings in June or July. Root in a 50/50 mix
of peat moss and sand. They should be well-rooted in 4 to 5 weeks and may then
be transplanted into 3 to 4 inch pots. When well established, they may be
transplanted on site or overwintered indoors in the pots for spring planting.
Cuttings may not be necessary because establishment from seed has been
observed in restorations.
Seed availability may be sporadic due to an insect pest.