Invasive Plant: Orange Hawkweed

Photo shows patch of green plants with tiny, paintbrush-like, orange flowers.
For a time, orange hawkweed was being spread in wildflower seed mixes. Always be suspicious of unlabeled wildflower seed mixes. Better yet: Don’t use them at all. Found in Multnomah and Clackamas counties and throughout North Oregon Cascades passes, orange hawkweed threatens to spread farther.
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At a Glance

  • Scientific name: Pilosella aurantiaca (formerly Hieracium auranticum)
  • Annual, perennial, or biennial? Perennial
  • Conditions it likes best: Rapidly spreads through lawns, flowerbeds, and meadows.
  • How it spreads: Primarily fluffy seeds spread by wind, but established plants send out difficult-to-see aboveground runners and belowground roots (rhizomes) to start new plants.
  • How it causes damage: Orange hawkweed quickly fills in open spaces, yards, and meadows. It forms dense patches and forces out other plants.
  • Best time and way to manage: From March to August, pull plants, dig up roots and runners, and cut off flowers.
  • Oregon Department of Agriculture noxious weed rank: A
  • Report patches of this plant? Yes. Oregon law requires that you report all sightings immediately for assistance. Use the online tool at Oregon Invasives Hotline or call 866-INVADER to let the State know when and where you found this plant. You may also contact Portland’s Environmental Services (contact information on this page), who will notify the State for you and help you remove these plants. A photo and location are required.

How to Identify Orange Hawkweed

Photo shows plants with small, orange flowers and fluffy white seedheads.
Orange hawkweed have dandelion-like flowers with orange-red centers. Photos by Michael Shepherd, USDA/Forest Service

Spring. Flat circles of leaves (rosettes) appear in March and April, eventually getting taller in May, with 1- to 2-foot-tall stems.  Their half-inch wide orange flowers are very obvious and appear in May and June.

Summer-Fall. Flowers turn into balls of white fluff soon after flowering, usually June or July.  These ripe seeds then blow around, starting new plants somewhere else.

Winter. Plants die back.

How and When to Remove Orange Hawkweed

  • Photo shows young green plants with fuzzy leaves.
    In the spring, orange hawkweed plants emerge as flat circles of leaves.
    Manual. Digging orange hawkweed can be effective, but remove as many roots and runners as possible. Digging is the best way to manage small patches.
  • Herbicide. Herbicide treatment options are limited in cities, but large patches in forested and rural areas have been more successfully managed with herbicide.  
  • Check. Check the site for new plants at least once a year and especially for the first 2-3 years after removal.
  • Replant. After a year or two of managing this plant, consider planting native or less aggressive non-native plants. There are now many groups who can suggest new plants.

Prevention is Best Practice

Clean your boots, pets, and maybe even your tires when you finish a hike or trail ride in Pacific Northwest natural areas, or if you have invasive plants on your own property. Cleaning boots and pets keeps invasive plants from spreading to new places. Be careful when trading plants with neighbors and fellow gardeners to make sure you’re not trading this or any other plant of concern.

Be Aware of Look-alikes

Hawkweeds are generally known for their hairy leaves, but without flowers, it is difficult to tell orange hawkweed from other hawkweeds. In flower though, there are no plants that look like orange hawkweed. Other hawkweeds have yellow or white flowers.

Properly Dispose of Invasive Plants

To prevent spreading invasive plants:

  • Never place plants or seeds in your compost or yard debris.
  • Never throw pulled plants on the ground or into the street or sidewalk.
  • Put all pulled plants, bulbs, or seeds into a plastic bag and put the bag in the trash.
  • Wash all garden tools and gloves.