Tansy ragwort

Jacobaea vulgaris

Tansy Ragwort1
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Tansy Ragwort - An herbaceous plant that can either be a winter annual, a biennial, or sometimes a perennial. Mowing may cause the plant to grow like a perennial.

Leaves: Twice divided leaves, with leaf stems at the bottom of the plant, but a singular, unbranched, stalk towards the top of the plant. First year Tansy will have a basal clump, and afterwards the leaves are alternate.

Flowers: Flowers bloom from June - August. Somewhat flat-topped clusters of yellow disk and ray flowers. Flowers have bracts (scales) with black tips.

Habitat: Commonly found in open, disturbed areas like roadsides, pastures, fields, and cleared forest areas.

Weed Classification: B Select

Why is it a Noxious Weed?

Tansy Ragwort is toxic to livestock and a threat to agriculture. The flowers are the most toxic part of the plant. Tansy also spreads quickly and will outcompete native vegetation, especially in open pasture settings.

Tansy ragwort is a widespread issue. If you are having difficulty controlling it on your property and would like to consult with us on control measures or are seeing Tansy on go uncontrolled on your neighbor's property, let us know.

Control Recommendations:

WA State Noxious Weed Board

PNW Pest Management Handbook

UC Davis Weed Report