Quick Facts…

• is a non-palatable, aggressive weed with allelopathic properties (it produces chemicals which inhibit growth of other plants). It becomes a major problem because Dyers Woad overtakes native grass, and most livestock and wildlife won’t graze it.
• plants occur in areas with poor, dry soils such as roadsides, rangelands, vacant lots, and open forests.
• was once known as a source of blue dye (indigo) in the 13th century, and it was widely cultivated in England until 1930. Establishment in the U.S. is traced to the early 1900’s as a contaminate in alfalfa seed.

Control

• In small isolated areas, cutting, mowing, and hoeing, before full flower, can be effective. These methods may need to be repeated throughout the growing season. Field tillage is also effective for short term control. It is important to keep this weed from producing viable seed.
• Herbicide products such as Escort and Telar are effective when applied to actively growing plants. Other products such as those containing 2,4-D or Dicamba have also been used. Treatments should be applied during the rosette through bolt stage. Always read and follow the label when using any herbicide.