Invasive Species: Mouse-ear Hawkweed

Hieracium pilosella

Mouse-ear hawkweed is a native of Europe and Asia

Why is it important to control?

Mouse-ear Hawkweed produces thick mats of rosettes crowding out other plants. It displaces desirable pasture species.

Yellow Mouse-ear Hawkweed Closeup

How can you identify it?

Two images, one of Mouse-ear Hawkweed flower, and one a closeup of the seedhead
Habitat: Over-grazed pastures, meadows, prairies
Life Cycle: Perennial
Height: 3-10 inches
Leaf Description: Oblanceolate-shaped leaves are arranged in a rosette. Leaves have long hairs on the upper surface and are light underneath.
Fruit & Flower Description: One yellow flower per rosette
Bloom Time: May to June

How do you control it?

  • For small areas, digging up is recommended.

  • Make sure to remove the entire root system and throw any plant material away in a tied plastic bag in the trash.

  • Removing flowers early in the blooming season can help prevent seed dispersal.

  • For larger infestations, herbicide may be used. Use a broadleaf selective herbicide and make sure to follow all label directions.

  • The Oregon Department of Agriculture has no biocontrol agents.

How to Report it?

There are various ways you can report this noxious weed.

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