Common mullein is a large tap-rooted biennial that reproduces by seed. The flowers are sulfur yellow with five petals and grow on large terminal spikes. The large leaves narrow toward the apex of the plant and are extremely wooly. Common mullein can grow to be 10 feet high, but is more commonly found in the 2-6 foot range.
Common mullein is invasive in disturbed soils and on well-drained rocky soils. In Teton County it’s a very problematic invader of roadsides and the levee system.
For advice on controlling this invader or for a free consultation of your Teton County residence, please contact Teton County Weed & Pest District at 733-8419.