TANSY RAGWORT

Tansy starts actively growing about mid-April and continues growth into September. The first year form of the plant is called a rosette and consists solely of rather dark green lobed leaves which are a little thicker than but similar to a dandelion. The second year plant has flowers which form an umbrel shaped cluster at the top of a long stalk. Each flower looks like a small ½" to 3/4" diameter yellow daisy with 13 petals. The plant, both first and second year, also has a chrysanthemum like smell to it.

It is normally a biennial plant (meaning it completes its life cycle in two years). However, if the plant has been damaged and not destroyed, it may easily become a perennial and return year after year until it's able to produce it's seed. This is the reason that often when you cut or pull tansy, it comes up again in the same place. For the forementioned reasons, it is best to remove the plant instead of mowing it. If you live in an area with loose soil, pulling the plant can be very effective since the roots will come with the plant easily. However, digging or pulling in hard or rocky soils often leaves small root fragments that regenerate several plants where there used to be only one.

Tansy is poisonous to livestock, causing liver damage which leads to eventual death. Once it is eaten, the harmful alkaloids stay in the animal's system, building up over the months or years that the animal continues to ingest additional Tansy (even in small amounts). Since the poisoning is cumulative there are no acute symptoms as there would be if an animal were to eat Bracken Fern or Yew. The signs of a Tansy condition are: lethargy and loss of appetite, crustiness around the eyes and nose, red and watery eyes that are especially sensitive to bright sunlight, diarrhea, wobbling and dragging of the feet, aimless wandering and apparent blindness, and in the latter stages the animal may develop a "pig like" odor and the abdomen will fill with fluid.

The economic loss due to tansy is difficult to measure. Anyone who has spent time and money trying to control it, or lost an animal because of it, is well aware of the expense that is involved. Good pasture and expensive livestock are worth keeping properly. Because of Tansy's ability to spread, 150,000 potential seeds from each plant, landowners without livestock or pasture land are also required to control Tansy's growth.

Most of the herbicides recommended are for broadleaf plants such as tansy or thistle, and can be used safely in pastures and around livestock when used in accordance with the label directions. More information about Tansy Ragwart as well as control recommendations are available at the Washington State Noxious Weed Board Web site.

If you have any questions, or would like to report a Tansy infestation, please call us at (253) 798-7263 weekdays between 7:30 am and 4 pm, or send an email message.