Teasel, a biennial introduced from Europe, has spread rapidly in North America over the last 20-30 years. This has been aided by the construction of interstates along which teasel happily grows. Its spread is also aided by it’s seeding habits. A single teasel plant can produce 2,000 seeds of which 30-80% germinate depending on a variety of conditions. Such aggressive seeding ability has allowed teasel to take over native prairie and savannah habitats.
AEM Inc. regularly removes and controls the growth of teasel. Controlling teasel is most often done in spring by spraying the teasel rosettes to inhibit their growth. Later season removal involves the mechanical removal and disposal of teasel that has not quite gone to seed.
Below, AEM Inc. surveys a site in Northbrook with the goal of removing the intermittent teasel rosettes (which are indicated by the flags).
Learn more about the natural history of teasel from the Prairie Research Institute.