Agronomy and Horticulture Department


Date of this Version



Insect Science, Plant Disease, & Weed Science, University of Nebraska Cooperative Extension, Institute of Agriculture and Natural Resources 87(6) (April 24, 1987)


Copyright 1987 University of Nebraska


In This Issue:

  • Musk Thistle Control
  • 1987 Weed Science Tour
  • David Mortensen Joins Staff at Lincoln

Musk Thistle Control

As the weather warms and the grass greens, musk and assorted other pasture thistles are set to compete, bolt, flower, and scatter seeds across the land. Springing from an innocent-looking flat rosette in late April to a gigantic seed factory in late June, this same scene repeats itself yearly. A robust musk thistle can produce 20,000 seeds. Last summer and fall had ideal weather for musk thistle seed production, germination, and rosette growth. With abundant root reserves, the thistles will be vigorous in 1987. The only effective way to control them chemically is by spraying the rosettes. Once the center stalk elongates, musk thistle has a much higher tolerance for herbicides and is not easily killed. So apply either 2,4-D at 1 1/2-2 qt/A, Banvel + 2,4-D at 0.5 + 1 qt/A, or Tordon 22K at 0.5 pt/A within the next two weeks. Normally May 1 to May 10 are the critical dates for musk thistle bolting across Nebraska from southeast to northwest.