Description: A member of the sunflower family, Texas blueweed (Helianthus ciliaris) is distinctive because of its bluish or grayish green foliage. Lance-shaped or narrow linear leaves are sessile (attached directly to the stem, without stalks) and may be alternate or oppositely arranged on the stem. The margins are wavy and bear short, stiff hairs. This plant is a rhizomatous perennial usually growing 1 to 2 feet tall with roots that reach as deep as 5 feet into the soil. The composite flower heads are 1 to 1-1/2" wide with yellow ray or marginal flowers (less than 1⁄2 inch long) and central reddish or purplish-brown disk flowers. Each plant may have 1 to 50 seed heads, with each of those containing 100 to 150 seeds.

• Mechanical: Depleting the plant's energy reserves by persistent pulling, digging and cultivation in combination with the use of herbicides and the establishment of perennial grasses may be the best strategy for control. Covering small infestations to prevent exposure to sunlight may also be a feasible method of control and/or eradication.
• Biological: Texas blueweed is resistant to the sunflower beetle and the carrot beetle.
• Herbicide: Dicamba, 2,4-D, Roundup, imazapyr, MCPA, picloram and clopyralid are all reported to control this plant, though data are lacking in the Pacific Northwest. Follow the label instructions for site specific information and refer to the annually updated Pacific Northwest Weed Control Handbook.Refer to the State Noxious Weed Control Board site

For More Information:
Detailed information about Texas Blueweed is available at the Washington State Noxious Weed Control Board Web Site.