Tansy Typhoon!

This year has brought us a particularly health crop of tansy ragwort. What do these plants look like? A sea of yellow along our roadways and in many fields. The stems are stout, branched and have a hint of purple at the base. Often, groups of stems arise from the plant crown. Its leaves are dark green on top, whitish-green underneath, and have deeply cut, blunt-toothed lobes with a ragged/ruffled appearance. Flower clusters develop on stout, leafy elongated stems that grow up to 6 feet tall; each flower cluster is composed of many bright-yellow flowers with (usually) 13 petals. This plant is a biennial plant that will set 150,000 seeds (per plant), which may lie dormant in the soil for as long as 15 years. Have you seen this plant in your neighborhood? Did you know that just by pulling one plant (bagging it and putting it in the trash) you can help drastically slow the spread of this invader? In Whatcom County one large road side site was completely controlled in 3 years just through pulling! You also have a friend in the fight to control tansy, the cinnabar moth larva. This yellow and black little larva eats the plant weakening it so that it will produce fewer seeds. Watch for it as you pull tansy in your area. If you see it, leave the plant stem but still take the seed heads with you.

Happy weeding!

Cinnabar Moth

Larva Eating Tansy