Tansy Ragwort

Why is it a Noxious Weed? Contact Us Tansy ragwort is toxic and can be lethal to cattle If you have questions about tansy ragwort or and horses, and to a lesser extent goats, and other noxious weeds, we can help. Please contact seldom sheep. All parts of tansy ragwort are toxic, us at: both in live plants and in dried material in hay. WA State Noxious Weed Control Board Tansy ragwort can also cause human liver damage, P.O. Box 42560 and should never be used as an herbal remedy Olympia, WA 98504 or tea. It can also taint milk consumed by people, 360-725-5764 Tansy Ragwort although it’s unlikely to do so in toxic amounts. Email: [email protected] Also, honey containing nectar from tansy ragwort http://www.nwcb.wa.gov tastes so unpleasant it can’t be sold. Senecio jacobaea Eric Coombs, Oregon Department of Agriculture, Bugwood.org Agriculture, of Department Eric Coombs, Oregon Or contact your local county noxious weed control board: For information on biological control of tansy ragwort, contact: Noxious Weeds in Washington Integrated Weed Control Project, “Noxious weed” means a plant that when WSU Extension established is highly destructive, competitive, 2606 W Pioneer Ave or difficult to control by cultural or chemical Puyallup WA 98371 A Toxic, practices. RCW 17.10.10 253-445-4657 Noxious weeds reduce crop yields, destroy native http://invasives.wsu.edu Noxious Weed plant and animal habitat, damage recreational opportunities, clog waterways, lower land values, and poison or harm people and livestock. in Washington Tansy ragwort is a Class B noxious weed in Washington State. While control of this toxic plant is mandatory in many Washington counties, we strongly encourage all landowners to control tansy ragwort. Check with your local county noxious weed control board or extension office to learn more about this and other toxic plants. Cover image: Michael Shephard, USDA Forest Service, Bugwood.org Identification Where does it grow? The young Tansy ragwort is a tap-rooted, biennial or rosettes of tansy Tansy ragwort often grows where land has perennial plant that is native to Eurasia. Young ragwort plants been disturbed, and where grass and other tansy ragwort plants form a rosette of coarse, can be especially plants are sparse. It typically occurs on ruffled leaves with reddish stems. Plants will dangerous to roadsides, in pastures, fields and cleared grazing animals grow one or more upright, leafy stems, 1 to 4 because they are forested areas. It is not particular to soil type. feet tall, the following year. hard to avoid It can be found growing throughout • Leaves are twice divided, deeply lobed as animals eat Washington but is more commonly found on surrounding grass. and alternately arranged on the stems. the west side of the state. • Flowerheads are in flat-topped clusters. Each flowerhead is daisy- like in appearance and is Control Chemical: Herbicides are effective against tansy a cluster of many small ragwort when applied to rosettes in the spring, Tansy ragwort control is best or applied to the new growth initiated after fall yellow flowers. There are done before the plant begins rains. Selective herbicides can be used that target generally 13 petals (ray to flower to prevent possible broadleaf weeds and not grasses. Remove and flowers). seed development. Plants bag plants that have already flowered as herbicide • At the base of the flowerheads there are have viable seed as soon as applied at that time will not stop seed production. generally 13 green bracts with dark tips. they begin to flower. Small Animals should be removed from areas that have infestations can be controlled been sprayed for two weeks. Always read the manually by pulling up the Hand-pulled tansy ragwort rosette. label instructions before applying any herbicides entire plant, including roots. If for proper rate and timing. Check with your you pull flowering plants, seal them in a plastic bag local county noxious weed board and the Pacific and put them in the trash—not in your compost or Northwest Weed Management Handbook yard waste. Large infestations are better handled http://pnwhandbooks.org/weed/ for specific by a combination of manual and chemical controls. herbicide recommendations. Bugwood.org Eric Coombs, ODA, After tansy ragwort control, plant areas with site Biological: The ragwort flea appropriate plants to provide competition and beetle (Longitarsus jacobaeae) reduce further tansy ragwort invasion. Monitor and the ragwort seed fly areas for seedlings and resprouts. (Botanophila seneciella) are Mechanical: Mowing is not effective as tansy biological agents used to ragwort can resprout if the roots are not removed. control populations of tansy Laurel Laurel Baldwin, WCNWCB Mowed plants will send up multiple stems and ragwort. Cinnabar moth flower at shorter heights. Mowing can be used as (Tyria jacobaeae) caterpillars Adult ragwort seed an interim measure to keep it from blooming and can defoliate tansy ragwort fly on tansy ragwort. going to seed but other control methods will be but can also feed on native and needed the same year before flowers form. Mowed horticultural species of Senecio and Packera, so or injured plants can behave as perennials, growing further redistribution of this moth is discouraged in new stems the following year. Dig up or pull the many areas. Other control treatments should not be entire plant when the soil is moist to remove the applied where insect agents are active. Contact the Blooming tansy ragwort with its characteristically whole root—root fragments left in the soil can WSU Integrated Weed Control Project or your local leafy stems. resprout. county noxious weed board for further information..

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