For Your Garden - October 2010
Native prairie wildflowers bloom well into fall! Are you using native wildflowers in your garden? Native species are adapted to the Illinois climate. They require little or no watering and are resistant to drought, insects and most diseases. They also provide food and shelter for native wildlife. Because they are perennials, you can welcome their presence year after year.
prairie dock (Silphium terebinthinaceum)
Photo © Illinois Department of Natural Resources
Prairie dock’s large oval or heart-shaped leaves develop only at the base of the plant. The leaves are toothed along the edge and may be two feet long and eight inches wide. The small yellow flower heads develop at the tip of a long stalk. The flower stalk may grow from six to 10 feet tall. Prairie dock grows in moist prairies throughout the state. It produces flowers from July through September. The leaves persist when dry and add interest to the garden through fall and winter.
Classification and taxonomy are based on Mohlenbrock, Robert H. 2014. Vascular flora of Illinois: A field guide. Fourth edition. Southern Illinois University Press, Carbondale. 536 pp.