T-Listed for Tansy Ragwort!

What You Need to Know About Tansy Ragwort

Here’s an update on Integrated Pest Management (IPM) for tansy ragwort after the recent damp summer weather. We managed to control it before the seeds started to drop. Hand pulling, spot spraying, and removal before seeds drop are essential. Covering 10 acres and finding only three known tansy plants is a success for Wyeast Gardens! Unfortunately, it will return next year, but we’ll be ready. This batch will be sealed and added to the burn pile for the Fall burning season.

If you live in Clackamas County, you've likely seen fields of yellow tansy. It’s widespread and dangerous. The flowers, roots, and stems are toxic to livestock, humans, and agriculture. In Washington State, this noxious weed is on the Quarantine List, prohibiting its transport, sale, or distribution.

We have co-developed a successful eradication program with Clark County, learning industry best practices. The situation in Clackamas County is serious, but not new to us.

Identification and Impact:

Scientific Name: Jacobaea vulgaris

• Appearance: Biennial weed with green ruffled leaves in its first year (rosette stage) and yellow flat-topped flower clusters in its second year. Flowers resemble yellow daisies but have 13 bracts with dark tips.
• Growth: Can reach up to 4 feet tall and spreads through numerous seeds.
  
• Toxicity: Highly toxic to livestock, humans, and agriculture. All parts of the plant are poisonous.
• Invasiveness: Extremely invasive and prevalent. In Washington State, it is on the Quarantine List, prohibiting transport, sale, or distribution.

Current Situation in Oregon:

• Classification: Tansy Ragwort is classified as a B category weed in Oregon. While regionally abundant, it requires intensive control at the state, county, or regional level.
• Spread: The Mt. Hood Corridor shows its rampant spread, suggesting a need for T-listing and prioritized eradication measures.

Noxious Weed Control Classification Definitions (Oregon State Weed Board, 2022):

• A Listed Weed: Known economic importance with small enough infestations for eradication or containment.
• B Listed Weed: Regionally abundant with economic importance, requiring intensive control.
• T-Designated Weed (T): Focus for prevention and control, receiving priority action.

Effective Tansy Ragwort Control Methods:

1. Hand Pulling:

• Wear protective gloves.
• Pull each weed with its roots.
• Seal pulled weeds in a bag and discard properly.
• Any remaining roots may resprout.

2. Spot Spraying:

• Use appropriate herbicides to prevent seed production.
• Follow herbicide labels strictly.
• Remove grazing livestock from sprayed areas for two weeks.

3. Biological Control:

• Ragwort Flea Beetle (Longitarsus jacobaeae): Effective in destroying tansy.
• Ragwort Seedhead Fly (Botanophila seneciella): Destroys developing seeds.

4. Mowing:

• Interim measure to prevent blooming and seeding.
• Mowing can spread seeds, potentially increasing future infestations.

5. Disposal:

• Seal pulled weeds and dispose of them properly.
• Burn sealed batches during the Fall burning season.

Community Efforts:

We encourage the community to join forces in eradicating Tansy Ragwort to protect our livestock and agriculture.

NEED HELP?

If you own a business or a home in Clackamas County and need assistance, our trained crew is ready to help. We have over 25 years of experience in landscaping and irrigation, and we are licensed, bonded, and insured.

Contact Us:

Phone: 503-680-1916

Email: Emma@WyeastGardens.net

Let's work together to eliminate this toxic weed and ensure the health of our community and environment!