United States Department of Agriculture Field Guide for Managing Teasel in the Southwest Forest Southwestern Service Region TP-R3-16-26 Revised June 2017 Cover Photos Top right: Ohio State Weed Lab, Ohio State University, Bugwood.org Top left: David Cappaert, Michigan State University, Bugwood.org Bottom: The Nature Conservancy, Bugwood.org In accordance with Federal civil rights law and U.S. Department of Agriculture (USDA) civil rights regulations and policies, the USDA, its Agencies, offices, and employees, and institutions participating in or administering USDA programs are prohibited from discriminating based on race, color, national origin, religion, sex, gender identity (including gender expression), sexual orientation, disability, age, marital status, family/parental status, income derived from a public assistance program, political beliefs, or reprisal or retaliation for prior civil rights activity, in any program or activity conducted or funded by USDA (not all bases apply to all programs). 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Submit your completed form or letter to USDA by: (1) mail: U.S. Department of Agriculture, Office of the Assistant Secretary for Civil Rights, 1400 Independence Avenue, SW, Washington, D.C. 20250-9410; (2) fax: (202) 690-7442; or (3) email: [email protected]. USDA is an equal opportunity provider, employer and lender. Printed on recycled paper Teasel (Dipsacus fullonum L.) Teasel family (Dipsacaceae) Teasel is an invasive plant that has been listed as a noxious • Flowers occur from early summer until early fall; weed in New Mexico. This field guide serves as the U.S. oval-shaped flower heads with rings of small, densely Forest Service’s recommendations for management of packed lavender flowers. Stiff, spiny, upward pointing teasel in forests, woodlands, and rangelands associated bracts (~ 2" long) extend from the end of the stem, with its Southwestern Region. The Southwestern Region below the flower head. Each flower usually lives only covers Arizona and New Mexico, which together have 11 1 day. national forests. The Region also administers 4 national • Reproduces mainly via seed; prolific seed producer grasslands located in northeastern New Mexico, western (2,000 seeds per plant; viable for 2 years). Oklahoma, and the Texas panhandle. Ecology Description Impacts/Threats Common teasel (synonyms: Fuller’s teasel, wild teasel, Teasel can be an aggressive competitor thereby allowing it Venus’ basin (or cup), barber’s brush) is a weedy biennial to displace desirable plants and form a monoculture. Its with prickly stems and a distinctive cone-shaped flower presence reduces forage availability and contributes to head. Originally introduced from Europe, teasel is valued declines in species diversity and range quality. In New as a horticultural plant and has also been used medicinally. Mexico, it has similar habitat preferences to the The spiny, dried seed heads of teasel are used for wool Sacramento Mountains thistle (Cirsium vinaceum) and may “fleecing” and are commonly used in floral arrangements. out-compete this endangered plant species locally. In the rosette stage, it is similar in appearance to thistles, Site/Distribution common burdock (Arctium minus), and broadleaf dock Teasel prefers open, sunny habitats; it is often common in (Rumex obtusifolius). As teasel matures, it can be disturbed sites, pastures, and along interstate highways. It distinguished from these other plants by its wrinkled grows in both moist and arid soils though it is most often leaves. found in mesic soil types. Growth Characteristics Teasel is widespread in the Pacific Northwest and is • Biennial or short-lived perennial (dies after it flowers becoming more common in New Mexico and Arizona. In for the first time). New Mexico, it prefers elevations between 4,000 and • Taproot grows during rosette stage; 2 feet deep. 7,000 feet and has been mapped in the Lincoln National Fibrous roots extend from taproot (up to 1-foot wide). Forest in Otero County. • Rosette leaves are wrinkled, scalloped, oval-shaped; Spread older rosette leaves are often hairy. Teasel prolifically produces seed that remains viable in soil for at least 2 years. Usually, seeds establish near the parent • A flowering stalk emerges when roots have sufficient plant, in spaces previously occupied by the basal rosette energy reserves, usually after growing as a rosette for leaves. For an isolated plant, the seeds will generally fall at least 1 year. The erect branching stem may grow to within 4 to 5 feet from the parent plant. However, as 7 feet tall with simple, stalkless, opposite, lanceolate population density increases, the potential area where seed leaves that have visible veins. Upper leaves grow to may fall expands. Seeds may be transported by birds or via 10" long, have entire margins, slightly clasp the stem, waterways such as irrigation ditches or streams/rivers. and may hold water near the leaf axil. Leaf mid-ribs Seeds are also spread by adhering to the undercarriages of and elongated stem have downward pointing prickles. vehicles or mowing equipment used along highways. 1 Invasive Features extent, density, and location of the infestation. Land use Although teasel is not known to have allelopathic and current site conditions (accessibility, terrain, properties, it is aggressively competitive. Openings within microclimate, other flora and fauna present, etc.) must also plant communities coupled with light soil disturbance are be considered. Other considerations include treatment an invitation for invasion. Its taproot provides access to effectiveness, cost, and number of years needed to achieve nutrients and soil moisture deeper within the soil profile. control. More than one control method may be needed for Teasel’s biennial life history allows it to take up space each site. within the plant community while it stores resources for Special Considerations reproduction. The stored resources result in increased seed production and greater germination success. The Sacramento Mountains range in southern New Mexico serves as habitat for the endangered Sacramento Mountains thistle (Cirsium vinaceum) which is protected under the Management Endangered Species Act of 1973. Portions of this mountain Prevention and early detection are the best management range within Otero County are also inhabited by local tools for teasel. Management should focus on maintaining populations of Wright’s marsh thistle (C. wrightii) which is healthy native plant communities and managing teasel a New Mexico-listed endangered species and a Federal before it can produce seed. A combination of control candidate for listing. Wright’s marsh thistle is also found methods and repeated treatments will improve in Eddy, Chaves, Guadalupe, and Socorro Counties in New effectiveness in managing infestations. Mexico. Both thistle species occur in wetland habitats such The following actions should be considered when planning as spring seeps and marshy edges of streams and ponds a management approach: that may be invaded by teasel. Information should be obtained from the U.S. Fish and Wildlife Service at (505) • Maintain healthy plant communities to prevent or 346-2525 before treating teasel in the Sacramento limit teasel infestations. This may involve improving Mountains and the aforementioned counties that could grazing management practices to prevent excessive possibly involve habitat of these endangered species. grazing or reseeding disturbed areas with desirable grasses and forbs. Physical Control • Use certified weed-free seed and hay; use pellets for Physical control methods work best on seedlings, rosettes, horses used in the back country. and partially established stands of teasel. In general, the effectiveness of physical control methods can be increased • Eliminate new populations of teasel as early as by combining physical methods with herbicide spraying possible, especially when in the seedling or rosette for long-term management of teasel. stage. Manual Methods • Combine mechanical, cultural, and chemical methods for most effective teasel control. Hand-pulling or cutting – Hoe or dig plants at the rosette to early bolt stage by cutting the taproot 1 to 2 inches • Implement a monitoring and follow-up treatment below the soil surface. When soil conditions allow it, plan for missed plants and seedlings. hand-pulling can be effective for smaller, less established • Detect, report, and map large infestations. Keep infestations. Removal is generally easier and more annual records of reported infestations. effective when soil is moist and plants are beginning to bolt, but before seed set. It is very important to pull up as Table 1 summarizes some management options for