Stem

  • Up to 4 ft. tall; branched at top; dry plants with attached seed pods remain standing into winter
Photo of dyer's woad
Dyer's woad flowering plant

Leaves

  • Lance-shaped, 1-7 in. long, bluish-green and lack hair (glabrous) with a distinct whitish mid-vein; edges (margins) are wavy to smooth, stem leaves are alternate with lobed base that clasps the stem 
Photo of dyer's woad rosette
Dyer's woad rosette

Flower

  • Yellow with 4 petals; occur in clusters that give plant a flat-topped appearance
  • Mature seed pods dark brown to black, oblong, flattened and suspended from a small stalk; each contains a single seed 
Photo of dyer's woad plant
 

Root

  • Deep taproot
Photo of dyer's woad next to a river.
 

Other

  • Grows well on a broad range of sites; often infests waste areas, roadsides, rangeland, pastures and crop fields; known to occur in Elko, Humboldt and White Pine counties
  • Biennial, but sometimes annual or perennial; reproduces by seed
  • Historically cultivated for use as a blue dye and as a medicine 
 

Control

  • Mow in early-flower to reduce seed production; spring tillage or digging individual plants prior to seed production can be effective
  • Apply 2,4-D to young, actively growing plants; apply aminocyclopyrachor, chlorsulfuron, imazapic or metsulfuronon pre- and post emergence
Peer Review Logo
Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B. 2020, Nevada Noxious Weed Field Guide – Dyer's woad, Extension, University of Nevada, Reno, Field Guide

Extension Associated Contacts

Heidi Kratsch
Heidi Kratsch
 

Also of Interest:

 
Photo of puncture vine plant
Nevada Noxious Weed Field Guide – Puncturevine
Puncturevine 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
 

Associated Programs

Master Gardeners at tabling event

Master Gardeners of Nevada

Program trains local gardeners to provide research-based horticulture information to Nevadans.

master gardener team sitting on tractor

Master Gardeners of Washoe County

Master Gardeners provide free, research-based horticulture information to Nevadans.

Garden plant and pest sprayers image by Olga Seifutdinova from Getty Images

Integrated Pest Management

Integrated Pest Management (IPM) is a strategy that reduces pests to tolerable levels with lower costs for the pest manager or home gardener and minimal effect on the environment. The IPM program at University of Nevada, Reno Extension focuses on identification and public education with resources for the community including classes, Spanish language resources and a pest directory.