January’s Weed of the Month, yellow starthistle (Centurea solstitialis), is a toxic plant that infests millions of acres in the western United States. It is native to Eurasia and was likely brought to North America as a contaminant in alfalfa. Though widespread throughout the western states, there are no known populations in Minnesota.
Yellow starthistle has many characteristics that favor its invasiveness. The plant is an aggressive colonizer of pastures, grasslands, ditches, and disturbed areas. It produces abundant seed for reproduction and the seed remains viable for 10 years. The seed spreads by wind, water, vehicles, wildlife, and by moving contaminated soil and hay. Yellow starthistle depletes soil moisture and decreases species diversity. It is also highly toxic to horses, causing a fatal nervous disorder called “chewing disease”.
This noxious weed on the eradicate list has distinctive identification characteristics. It has yellow flowers with sharp spines at the base of the flower. The spines can injure eyes, noses, and mouths of livestock. An annual plant, it forms a rosette in the fall with lobed leaves. When it sends up the flowering stem in the spring and summer, the branches and stems are rigid and spreading. The stems and leaves are covered in white hairs that give it a grayish color.
Residents of Minnesota are asked to be on the lookout for yellow starthistle and to report sightings to the Minnesota Department of Agriculture. Management strategies are aimed at preventing seed formation and spread, and include the following:
As a noxious weed on the eradicate list, all above and below ground parts of the plant must be destroyed. To report infestations of yellow starthistle or any other noxious weeds on the eradicate list, please contact Arrest the Pest by voicemail at 888-545-6684 or email at email@example.com.