Weed of the Month
Learn about noxious weeds and steps you can take to manage or eradicate. Each month we will bring you a new profile and helpful resources.

February Weed Profile
Common mullein
Verbascum thapsus
Common mullein, also known as woolly mullein, was introduced into the United States in the mid 1700’s. It was used as a fish poison for easy collection of fish. Introduction into Colorado is not known but was noted as a common weed in Boulder in 1905. This species occurs in all states to include Alaska and Hawaii and is often mistaken as a native plant.
First year plants have soft, fuzzy leaves that are gray-green. Second year plants can grow to more than 7 feet tall, leaves and stem are covered with woolly hairs.
Plants flower from June to August. Flowers are yellow, saucer-shaped and attached to an erect stem.
Common mullein is a biennial plant that reproduces by seed. It can produce 250,000+ seeds per plant. Seeds have been known to germinate after more than 100 years. Common mullein seed was found in archaeological soil in Denmark, this seed was dated from 1300 AD and germinated.
Integrated management techniques include chemical, and mechanical. If flowering, bag and dispose of plants to prevent the spread of seeds.
RESOURCES
Items of Interest
Weed of the Month
2021
January Weed Profile – Dalmatian Toadflax
2020
January Weed Profile – Cheatgrass
February Weed Profile – Myrtle Spurge
March Weed Profile – Hoary Cress
April Weed Profile – Leafy Spurge
May Weed Profile – Scotch Thistle
June Weed Profile – Dyer’s Woad
July Weed Profile – Orange Hawkweed
August Weed Profile – Purple Loosestrife
September Weed Profile – Teasel
October Weed Profile – Canada Thistle
November Weed Profile – Russian Knapweed
December Weed Profile – Russian Olive




