The issue: Western salsify

Western salsify (Tragopogon dubius) is an invasive weed from Eurasia and Northern Africa, that dies after seed production (monocarpic). Seed production can happen one to 14 (usually two to four) years after germination.

Although it has grass-like leaves it is classified as a broadleaf plant. The plant has a milky sap. The first growing season it forms an upright rosette, then the second season it bolts and forms a flower.

The yellow flower is borne on a hollow, 1- to 3-foot stem. Due to its deep taproot salsify does well in dry locations. The 3- to 4-inch seed head resembles a large dandelion.

Western salsify only reproduces by seed, so control efforts should focus on eliminating seed production. The seeds may germinate just about anywhere. It is often found in empty lots, pastures, rights-of-way, ditch banks, open rangeland and home landscapes.

Integrated pest management options:

· Prevention: Keep ditch banks free of seed-producing plants; clean all equipment and vehicles of weed chaff; feed weed-free hay; manage pastures for good competition; establish desirable plants in disturbance areas.

· Mechanical: Removal of the root 2 inches below the crown greatly reduces its ability to regenerate; mowing is not effective.

· Cultural: Promote competition of desirable plants.

· Biological: Intense, early grazing may reduce a thick stand by 25% to 50%.

· Chemical: A 2,4-D/dicamba combination in spring and fall works well. Herbicide on flowering plants is not effective. Be aware of tree and shrub roots in the treatment area. Be sure the target weed and crop or landscape situations are listed on the product label. Always read and follow herbicide label directions.

Combine them:

Western salsify seed remain viable for only a couple of years in field conditions. Combine different IPM options to help improve the effectiveness of your efforts.

For more information, contact Ron Patterson, University of Idaho Extension Horticulture/Agriculture Educator in Bonneville County, at 208-529-1390 or rpatterson@uidaho.edu.