Information on reporting teasel infestations
Cutleaf teasel is a threat to Minnesota’s pastures and natural areas. Native to Europe, teasel was introduced as early as the 1700s, for both industrial and ornamental purposes. The fabric industry placed teasel on spindles then spun fabrics across to raise the nap of fibers. Gardeners plant cutleaf teasel for its stately form. Flowers and seedheads are used in dried floral arrangements. Cutleaf teasel escaped cultivation and now displaces desirable vegetation. The related common teasel was similarly used and was also a source of wool dye.
Teasels are monocarpic perennials (produce seed only once in a lifetime) that form basal rosettes for at least one year until enough resources are acquired to send up flower stalks. Rosettes develop oblong, hairy leaves and large tap roots. The small, dense white flowers occur on oval-shaped, terminal heads enclosed by stiff, spiny bracts. Flower stalks may grow to over 7 feet in height. Blooming occurs from July through September. After flowering and seed production, the plants die. Leaves on the flowering stalks are large, deeply-lobed, opposite, and wrap around the stem forming cups that can hold water. Both the leaves and stems are very prickly. Teasels also exhibit a characteristic shared by many weedy species – elasticity – that enables it to quickly produce abundant seeds on very short stalks after mowing.
The related common teasel, D. fullonum, is also considered invasive but has not been reported in Minnesota. It would be expected to thrive here since it has wide distributed in most of the lower 48 states. It can be distinguished by the un-lobed lance shaped leaves and typically pink flower color.
Cutleaf teasel grows in open, sunny habitats such as roadsides and pastures. It prefers disturbed areas, but can invade high quality areas such as prairies, savannas, seeps, and sedge meadows.
Means of spread and distribution (View cutleaf teasel distribution)
Teasels are prolific seed producers with most seed falling near the parent plant. The result is expansion of existing infestations. Long range dispersal to start new infestations can occur by a variety of means. Seed can float along riparian corridors, drift with the snow, journey along transportation corridors and recreational trails from seed shed from soil on tires and vehicle under carriages. It can be spread on mowing equipment. Teasel has been noted in or near graveyards, spread by seed from dried floral arrangements. Birds can consume then distribute teasel seeds. It can be found in all northern states from Massachusetts to Colorado and in Oregon. In Minnesota, cutleaf teasel is reported in multiple counties including Clearwater, Houston, Hubbard, Mower, Olmsted, Pope, Ramsey, St. Louis, Wabasha, and Winona.
The teasels form large dense stands that choke out desirable plant species. This can reduce forage, wildlife habitat, and species diversity.
Prevention and management
Do not plant teasels or intentionally move soil, including soil adhered to recreational vehicles or lawn/garden equipment, containing seed of this species. Do not use seedheads in floral arrangements.
Infestation sites will need to be monitored and treated repeatedly until the seedbanks are depleted. Teasel seedbanks remain viable for a relatively short time, 3-5 years. With diligent control, eradication may be feasible within this timeframe.
Both cutleaf and common teasels are prohibited noxious weeds on the eradicate list. This means that all of the above and below ground parts of the plant must be destroyed, as required by Minnesota Statutes, Section 18.78. Additionally, no transportation, propagation, or sale of these plants is allowed.
Photos Minnesota Department of Agriculture
If you suspect you have seen this plant in Minnesota:
Invasive Species Exclusion Unit "Arrest the Pest" Hotline
1-888-545-6684 (toll free)
Minnesota Department of Agriculture (MDA), 625 Robert Street N, St. Paul, MN 55155-2538, email@example.com