Common Mullein

Common mullein is a biennial to short-lived perennial forb in the Scrophulariaceae (figwort) family. It grows from a taproot to form a basal rosette in its first year of growth; in the second year of growth, it produces a single stem that may reach up to 10 feet tall. Leaves are gray-green in color and covered in dense, wooly hairs. Leaves are oblong to oblanceolate and large, reaching between 4 and 12 inches long and 1 and 5 inches wide. Rosettes have a cabbage-like appearance. Leaves are alternate and decrease in size up the plant. Common mullein flowers on spike-like racemes from mid-spring to late summer. Flowers are small, yellow, and 5 petaled. Seeds are small and dark. Flower spikes are somewhat woody and may persist in the environment for several seasons after the rest of the plant has died.

Common mullein is native to Eurasia and was intentionally introduced to North America in the mid-1700s for various purposes including medicinal properties and use as a piscicide. It spreads solely by seed. Seeds are dispersed by humans, wildlife, livestock, and water, and common mullein is frequently found in disturbed sites including levees, roadsides, landscaping, wildlife wallows, and eroded embankments.

Prevention and cultural control strategies should be utilized as much as possible.

There are several biological control agents available for common mullein, but only one has been able to establish and overwinter in Teton County: seed head weevil (Rhinusa tetra).

Because common mullein has a taproot, it can be readily managed by hand pulling or digging out the root. Tilling or hoeing can be effective in reducing existing plants; however, soil disturbance stimulates germination of common mullein seeds in the seedbank. Controlled grazing is not frequently effective because livestock avoid foraging on common mullein. Mowing or chopping are not effective in preventing seed production unless continued throughout the entire growing season or coupled with herbicide treatments. Do not mow while seeds are present.

Larger infestations can be controlled with herbicides. Spring and fall treatments of rosettes are recommended, but treatment of bolting plants can be effective. Flowering plants may be chopped and the remaining rosette and stem treated with herbicide to prevent reflowering. Read the label before using any herbicide. Contact TCWP if you have any questions about application rates or how to use an herbicide

• Weed Report: Common and moth mullein from Weed Control in Natural Areas in the Western United States (2013) DiTomaso, Kyser et al. University of California. https://wric.ucdavis.edu/information/natural%20areas/wr_V/Verbascum_blattaria-thapsus.pdf‍
• Common Mullein: Rangeland, pasture, and riparian site recommendations (2009) Colorado Department of Agriculture. https://drive.google.com/file/d/1G1yVlMSKgIUU3bx78Z_Msq6mODnHmJiz/view
• Field Guide: Mullein. Missouri Department of Conservation. https://mdc.mo.gov/discover-nature/field-guide/mullein
• Fact Sheet: Common Mullein (2005) Plant Conservation Alliance’s Alien Plant Working Group. https://www.invasive.org/alien/fact/pdf/veth1.pdf