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Invasive Plant: Goatsrue

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Photo shows a mass of plants with spikes of purple flowers.
Harmful to livestock – not just horses and cattle – goatsrue is a threat to all of Oregon. Brought into Utah in the late 1800s, goatsrue is now found in several other states. Fortunately, goatsrue is still only found in a handful of places in Oregon, almost all in the Portland metro area.
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At a Glance

  • Photos shows green plant with compound leaves, each with several leaflets along the sides and one at the end. Purple flowers at the center.
    Goatsrue has compound leaves, each with several leaflets along the sides and one at the end. Leaflets often have a small fleshy point, though weather and conditions can cause them to break down.
    Scientific name: Galega officinalis
  • Annual, perennial, or biennial? Deep-rooted perennial that regrows each year
  • Conditions it likes best: Mix of sun and shade
  • How it spreads: By seed. Each plant can produce large numbers of seed (around 15,000), which are still able to sprout after 30 years in the soil.
  • How it causes damage: Forms dense patches with deep, tough roots. Toxic to livestock, especially sheep and goats.
  • Best time and way to manage: Digging is not known to be effective but might be, if there are just a few plants. Herbicide should be applied once or twice in the spring and once in the late summer or fall.
  • Oregon Department of Agriculture noxious weed rank: A
  • Report patches of this plant? Yes. City code lists this as a Required Eradication species. Report all sightings to Portland’s Environmental Services (contact information on this page).  Management of this plant is required, but free help is available. A photo and location are required.

How to Identify Goatsrue

Photo shows a hand holding up a plant with two leaves opposite each other and a hollow stem in the middle.
Look for a hollow stem when trying to identify goatsrue from other plants in the pea family.

Like all plants in the pea family, goatsrue has compound (multi-part) leaves. Goatsrue, though, has relatively tall (3- to 6-feet), hollow stems. These stems are quite different from vinier vetches and wildpeas.

Fall-Winter. These plants are not visible in fall or winter.

Spring. Plants emerge April through May. Goatsrue has compound leaves, each with several leaflets on each side and one leaflet at the end. Leaflets often have a small fleshy point, though weather can cause them to break down. Plants with tendrils are not goatsrue.

Summer. Goatsrue flowers in early summer and forms seeds by July. Flowers are pale purple or sometimes white. Like many members of the pea family, goatsrue seeds form in pods which dry late in the summer. Sometimes the pods explode (like Scots broom), but more often the pods twist apart.

How and When to Remove Goatsrue

  • Photo shows brown seed pods.
    Clip seedpods and throw them in the trash.
    Manual. Because of its deep roots, manual removal is probably not a good long-term strategy. Clip any flowers or seedpods you see and throw them in the trash. Regular visits to the site are necessary to deal with the new flowers that usually occur later in the growing season.
  • Herbicide. Certain herbicides, used at the right time, can be effective.
  • 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

Goatsrue is in the pea family, which contains many familiar species. Brooms (Scots, Spanish, French, etc.), lupines (many are native!), clovers, and black locust are some of the common plants of the pea family in the Pacific Northwest. 

The vetches and wild peas look somewhat like goatsrue, but they are viny and creep along the ground or over other plants. Small tendrils twist around nearby objects for support. Goatsrue has a tall, straight stem and no tendrils. Both goatsrue and its cousins create pea-like seedpods, though goatsrue pods are smaller, less smooth, and more twisted than a pea.

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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