Echium valgare • Class B

Both stems and leaves of Blueweed are covered with short, stiff hairs, and spreads only by seed. stiff hairs. Flowering stem grows to over 36 inches tall and generally has conspicuous dark flecks at the bases of some hairs. Leaves are lance shaped, the undersides often have dark flecks and they grow in an alternating pattern, becoming smaller and stalk-less moving up the stem. Plants bloom from June through August; seeds mature about a month after bloom. The bright blue, funnel shaped flowers are arranged on the upper side of the stems. Buds are reddish-purple, becoming bright blue at full bloom.

Each plant can produce up to 2,800 seeds that can remain viable in the soil for several years.

Blueweed does well in a variety of soil types, including poor soils, but does not tolerate shade. It grows on rangeland, rocky pastures, roadsides, waterways, and vacant lots.

It is considered unpalatable to livestock because of its coarse hairs and toxic alkaloids.

• The most effective control of Blueweed is prevention. Above all, prevent plants from going to seed.
• There is currently no known biological control agent available for Blueweed.
• Selective, translocated herbicides such as Picloram (used in Tardon and Grazon) and 2, 4 D are two herbicides that can be effective on blueweed.
• Spot spraying with an herbicide containing the active ingredient glyphosate (used in Roundup Pro, or Glyphos) can also be effective. Glyphosate is non- selective however, and will injure any plants that it comes in contact with. Spot applications should be applied at bud stage, prior to blooming.
• Carefully read and follow all herbicide label directions and restrictions. When using herbicides, read and follow all label instructions and obey all label precautions. (Note: pesticide product registration is renewed annually and product names and formulations may vary from year to year.)

 Download our Flyer or visit Washington State Noxious Weed Control Board Here. Photo by Leo Michels