Musk Thistle
Scientific Name: Carduus nutans

History/Origin
          Also known as nodding thistle, this plant comes from southern Europe and Asia. It now occupies a number of temperate zone areas in the northern and southern hemispheres of the world. Imported from Europe, the earliest record of this plant being found in America was in Pennsylvania, 1852.

Biology/Ecology
          A musk thistle plant relies on seed development for reproduction, and can produce over 100,000 seeds annually (average is 10-11 thousand). One interesting feature of this plant is its ability to self-pollinate. This allows single plants to reproduce and form populations without the need for cross-pollination. Ninety percent of this plant's life is spent as a rosette. After sending up flowering stalks, musk thistle can produce seeds in 45-55 days. When shed, these seeds are dispersed by wind, water, wildlife, livestock, and humans. Seeds can remain dormant in the soil for over 10 years, but usually about a third of them germinate and grow into seedlings.

Known Impacts
Detrimental:
           This plant can reduce the number of desirable plant species in an area 50 to 100 percent larger than the area occupied by thistles themselves. This reduces available forage and habitat for domestic animals and wildlife. Its dense growth form and spiny nature inhibits the use of an area by people and animals.

Beneficial:
           Seeds provide a source of food for some animals. It has been used for food and medicine.

Potential Locations
          Musk thistle moves into disturbed sunny areas and establishes well on bare soil. It can grow under a wide range of conditions (arid to moist), and can be found in saline or acidic soils up to an elevation of 8,000 feet. Musk thistle is common in areas of snow accumulation (along fences, ditches, and in brush patches) and invades degraded pasture, forestlands, rangelands, ditch banks, waste areas, and stream banks.

Control/Management
          Control methods must be maintained for 10 years to prevent reestablishment by dormant seeds.
• Herbicide and biological control are the most effective tools to combat this plant (example herbicides: Curtail, Tordon 22K, Escort, Telar [look at herbicide label: free search]).
• Plowing is not recommended for control because it cuts and scatters the roots, enabling them to resprout.