Dyer’s woad is a biennial plant that can grow from 1-4 ft. (0.3-1.2 m) tall. First years growth is represented by a rosette of hairy, bluish-green leaves 1.5-7 in. (3.7-18 cm) long. Stem leaves are lance-shaped and alternate with a cream-colored mid-rib. Yellow flowers with four petals appear in small clusters at the top of the stems in spring to late summer. Seed pods are flattened, 3/8 in. (0.9 cm) long, ¼ in. (0.6 cm) wide and hang from short stalks at the ends of the stems. Dyer’s woad is native to central Asia and northern Russia and was introduced to North America in the early 1900’s as a contaminant in alfalfa seed. Plants occur in areas with poor, dry soils such as roadsides, rangelands and open forests.
Identification, Biology, Control and Management Resources
