What is the species?
- Hieracium auranticum (orange hawkweed)
- ODA “A” rank
Orange hawkweed, native to central Asia, does well on both sides of the Cascades. For a time, this species was being spread in wildflower seed mixes.
Why are we concerned?
Orange hawkweed is known to form dense patches that begin in open, disturbed areas. It has persistent root systems which do not respond well to some herbicide treatments, making management of established populations difficult. Orange hawkweed infestations can lead to:
- Reduced plant and animal diversity as other species are choked out
- Diminished agricultural value
How does it spread?
Orange hawkweed is primarily spread by fluffy seeds, although new plants are often formed by above-ground runners. Orange hawkweed seeds are moved around by:
- Hiking boots
- Nursery trade
What does it look like?
Orange hawkweed is most identifiable by its ½-inch wide orange flowers. Plants die back in winter to a flat rosette, forming new 1-2 foot tall stems in June. Established populations will often be a dense mat of plants. Orange hawkweed has distinctly hairy leaves.
Are there any lookalikes?
Hawkweeds are generally known for their hairy leaves, so telling them apart in winter is challenging. When flowering, there are no species that look like orange hawkweed.
How do we deal with it?
- Manual: Digging orange hawkweed can be effective, but care must be taken to remove all the root.
- Herbicide: Herbicide treatments are still in the trial phase in Portland.
How can folks help?
If you suspect you’ve found orange hawkweed, call either the City of Portland or contact the Oregon Department of Agriculture. ODA also REQUIRES landowners to report the presence or suspicion of target species like orange hawkweed.