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Invasive Plant: Paterson's Curse

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Photo shows light green stems with pink-purple flowers against a background of dry brown grass.
Paterson's curse is poisonous to grazing animals. Although it likes hot, dry weather, it has been seen in Portland. It may have come to Oregon packaged in a wildflower seed mix. Always check all wildflower seed packets to be sure they don’t contain this or other invasive plants.
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At a Glance

  • Photo shows a close up of light green stems with pink-purple flowers.
    Paterson's curse requires professional management. All sightings should be reported.
    Scientific name: Echium plantagineum
  • Annual, perennial, or biennial? Annual or biennial
  • Conditions it likes best: Oak woodland, native prairie, and dry upland slopes. Able to live in both wet and dry sites, it grows very well in drought conditions and grows faster than many other plants in low-water situations.
  • How it spreads: Spreads by making a lot of seeds that attach to people and animals.
  • How it causes damage: Poisonous to livestock and wildlife.
  • Best time and way to manage: Paterson’s curse has been found once in Portland. It requires professional management.
  • 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 of Oregon for you and help you remove these plants. A photo and location are required.

How to Identify Paterson's Curse

Photo shows green plant with pink and purple flowers.
Paterson's curse was possibly introduced to Oregon as seed in a wildflower mix. It is poisonous to livestock and wildlife. Photo by Tim Butler, Oregon Department of Agriculture.

Paterson’s curse plants are 1 to 3 feet tall with multiple branches and lots of tough hairs on the stems and leaves. Stems are light-green, bristly, stout, branching mainly toward the top. Leaves alternate and are green to light-green, hairy, and thick.

Flowers are most often blue-purple, but may be pink or white. Blooming usually starts in June, but some flowering plants can be found at any time of year.

How and When to Remove Paterson's Curse

Native to southern Europe and western Asia, Paterson’s curse is mostly found in Southwest Oregon. However, one patch was known in Portland in the 2000s.

  • Requires professional management. Paterson’s curse is a high priority plant and would be managed by professionals from the City or the State. This plant is on Oregon’s and Portland’s required eradication list, so it is important to report any plants found so they can be removed.
  • 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.

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

There really aren’t any plants that look like Paterson’s curse.

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.

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