2023 Invasive Plant Treatments Have Begun on the Wallowa-Whitman National Forest

EASTERN OREGON – (Release from the U.S. Forest Service) The Wallowa-Whitman National Forest has begun an integrated approach to reduce the risk of spread of invasive plant species across the Forest. Tactics include manual (hand pulling), mechanical, herbicide, biological control, aerial spraying, and cultural treatments. This work is being implemented under the 2010 and 2016 Records of Decision for the Invasive Species Treatment Project. 

Invasive species negatively affect biodiversity, wildlife habitat, wildlife and domestic livestock forage, and streamside vegetation. Invasive plants targeted for treatment include leafy spurge, meadow hawkweed, orange hawkweed, sulfur cinquefoil, whitetop, knapweeds, rush skeleton weed, Scotch thistle, Turkish thistle, Medusahead rye Canada thistle, whitetop, yellowstar thistle, yellow toadflax, Japanese knotweed, puncturevine, rose campion, hound’s tongue, and bugloss. 

Treatment sites are located across the Wallowa-Whitman National Forest and will be posted at the time of treatment. A blue marker dye that will fade over time will be mixed with herbicides to alert people of where product has been applied. 

Herbicides to be used include aquatic labeled glyphosate, aquatic labeled imazapyr, aminopyralid, chlorsulfuron, clopyralid, imazapic, metsulfuron methyl, triclopyr and picloram. Manual and mechanical treatments are planned for a number of small infestations, some of which have been treated for over a decade and are subsequently greatly reduced in size. Herbicide treatments will be carried out following the project design features of the Record of Decision for the Invasive Plants Treatment Project.

Treatment on the forest is expected to continue through October. The majority of herbicide treatments will be spot application to individual invasive plants using truck sprayers, backpack sprayers and UTVs. Some broadcast application is also planned along a small subset of roadsides and gravel pits. 

Partners include the Tri-County Weed Department (Baker, Union, Wallowa), Wallowa Resources, and Oregon Dept. of Agriculture.

For more information on the invasive plant program, including maps of potential treatment sites, please visit the forest’s website at: Invasive Plants and Animals.



For more specific information on timing and location of herbicide treatments, please contact the local Ranger District Office coordinators: 

  • La Grande and Whitman Ranger Districts, Scott Schaefer – (541) 962-8550
  • Hells Canyon NRA, Eagle Cap and Wallowa Valley Ranger Districts, Beckijo Wall – (541) 426-5535

For additional information contact Adrian Cuzick, Wallowa-Whitman National Forest Range and Invasives Programs Manager, at (541) 523-1279.