Stem

  • 2-6 ft. tall and sometimes wooly and branched; spiny wings caused by leaf bases that extend down the stem
Photo of musk thistle plant with pink flowers
 

Leaves

  • Dark green with a light-green midvein, 4-15 in. long, alternate and sometimes hairy; edges (margins) are deeply lobed and spiny
Photo of musk thistle rosette
 

Flower

  • Pink to purple (occasionally white), up to 3 in. wide, each located at the tip of a stem; head often nods or droops; stem below head usually spineless
  • Base of flower is covered with green, purple- or straw-colored, spine-tipped bracts; bracts are 0.1-0.3 in. wide, lance-shaped and sometimes hairy
Photo of musk thistle pink flower
 

Root

  • Deep, fleshy taproot
Photo of musk thistle plants with pink flowers

Other

  • Often infests roadsides, pastures and waste areas; known to occur throughout Nevada
  • Biennial; reproduces by seed; also known as nodding thistle
 
 

Control

  • Mowing, tilling or hand removal after bolting but prior to flowering is effective; remove the top 2 in. of crown by digging before seed production 
  • Several biological controls are available
  • Apply 2,4-D, chlorsulfuron, clopyralid, dicamba, glyphosate, picloram, or triclopyr to young actively growing plants; aminopyralid, imazapic, imazapyr, metsulfuron, or sulfometuron preemergence or post emergence on young plants
Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B. 2020, Nevada Noxious Weed Field Guide – Musk thistle, Extension, University of Nevada, Reno, Field Guide

Learn more about the author(s)

 

Also of Interest:

 
Photo of canada thistle plant.
Nevada Noxious Weed Field Guide – Canada thistle
Canada thistle is a noxious weed that has been identified by the state of Nevada to be harmful to agriculture, the general public, or the environment. Learn more about this weed.
Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B. 2020, Extension, University of Nevada, Reno, Field Guide
Photo of malta starthistle plant with yellow and pink and red flowers
Nevada Noxious Weed Field Guide – Malta starthistle
Malta starthistle is a noxious weed that has been identified by the state of Nevada to be harmful to agriculture, the general public, or the environment. Learn more about this weed.
Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B. 2020, Extension, University of Nevada, Reno, Field Guide
photo of perennial sowthistle patch
Nevada Noxious Weed Field Guide – Perennial sowthistle
Perennial sowthistle is a noxious weed that has been identified by the state of Nevada to be harmful to agriculture, the general public, or the environment. Learn more about this weed.
Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B. 2020, Extension, University of Nevada, Reno, Field Guide
Photo of purple starthistle
Nevada Noxious Weed Field Guide – Purple Starthistle
Purple starthistle is a noxious weed that has been identified by the state of Nevada to be harmful to agriculture, the general public, or the environment. Learn more about this weed.
Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B. 2020, Extension, University of Nevada, Reno, Field Guide
Photo of iberian starthistle plant with pink flower on top
Nevada Noxious Weed Field Guide – Iberian starthistle
Iberian starthistle is a noxious weed that has been identified by the state of Nevada to be harmful to agriculture, the general public, or the environment. Learn more about this weed.
Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B. 2020, Extension, University of Nevada, Reno, Field Guide
 

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Integrated Pest Management

Integrated Pest Management program is a long-term management strategy that uses a combination of tactics to reduce pests to tolerable levels with potentially lower costs for the pest manager and minimal effect on the environment.