U.S. DEPARTMENT OF THE INTERIORBUREAU OF LAND MANAGEMENT
A stout, erect winter annual, biennial, or short-lived perennial in the mustard family.
Stems Erect, somewhat woody, ranging in height up to 4 feet.
Leaves have a distinct cream-colored midrib and powdery white film on the upper leaf surface.
Flowers are small and yellow (3mm in width), located in dense, flat-topped racemes. Each flower has the four petals in a cross-shape characteristic of the mustard family.
Seed/Fruit are purplish-brown, tear-drop shaped, winged and pendulous.
Dyer’s Woad thrives in light sandy to gravelly soils and will even grow in rocky soil.
Unlike other mustards, it does not require disturbance to become established.
Dyer’s woad impacts the natural plant communities by outcompeting native plants. It causes a loss of wildlife and livestock forage by displacing native grasses and other native species. It is unpalatable to livestock, but not toxic.
Mechanical: Cultivation of the rosettes prior to bolting and flowering can eliminate newly established populations. Mowing is less effective due to the woody stems and the ability of the plants to resprout from the crown.
Chemical: Chlorsulfuron and metsulfuron methyl are effective if applied at the bolt to bud stage of growth in the spring and early summer.
Biological: A native rust pathogen, Puccinia thlaspeos, readily infects the rosettes of Dyer’s Woad. However symptoms are rarely obvious until the second year.