Malheur National Forest to begin invasive plant treatments

JOHN DAY, PRAIRIE CITY & HINES, OR – (Press Release from the Malheur National Forest)

The Malheur National Forest will soon begin invasive plant control on the forest. Control will be conducted using an integrated approach, including prevention; manual, mechanical, herbicide, biological control and cultural treatments; and restoration work.

Invasive plant control is a continuation of work implemented under the 2015 decision for the Malheur Site-Specific Invasive Plants Treatment Project and the forest plan amended by the Pacific Northwest Region 2005 decision for Preventing and Managing Invasive Plants.

Invasive species negatively affect biodiversity, wildlife habitat, wildlife and domestic livestock forage, and streamside vegetation. Invasive plants targeted for treatment include knapweeds, non-native thistles, St. Johnswort, houndstongue, sulphur cinquefoil, toadflaxes, whitetop, perennial pepperweed, and leafy or myrtle spurge.

Invasive plant control on the forest will begin this spring and should continue through October. Most herbicide treatments will be spot application to individual invasive plants using backpack or hand sprayers from ATVs or trucks. Some broadcast application is also planned along a subset of roadsides and gravel pits.

Treatment sites are located across the Malheur National Forest and herbicide treatments in high-use areas will be signed 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 allowed for use include aminopyralid, chlorsulfuron, clopyralid, glyphosate, imazapic, imazapyr, metsulfuron methyl, sethoxydim, sulfometuron methyl, and triclopyr. Manual, mechanical, and biological control treatments will also occur. All treatments will be carried out following the project design features of the Record of Decision for the Invasive Plants Treatment Project.

We typically avoid herbicide application in apparent edible and medicinal plant collection areas. You can contact us with your planned collection areas if you would like for us to avoid them or consider other appropriate invasive control strategies.

The following campgrounds will have no herbicide use in 2022: Middle Fork on the Blue Mountain Ranger District, Crescent on the Prairie City Ranger District, and Falls on the Emigrant Creek Ranger District. Roads and invasive patches nearby but outside of these campgrounds may still receive herbicide application. The remaining campgrounds will have at least half the campground herbicide-free in a 30-day period.

A map of potential treatment areas is posted on the forest’s website on the planning page under the invasive plant program menu or from the Invasive Plants Treatment Quick Link.

Partners include Grant Soil and Water Conservation District, Harney County Weed Control, Harney Cooperative Weed Management Area, Burns Paiute Tribe, Monument Soil and Water Conservation District, North Fork John Day Watershed Council, Oregon Department of Agriculture, Rocky Mountain Elk Foundation, private landowners, and permittees. Funding includes appropriated dollars and grant money from Title II projects.

For more specific information on timing and location of herbicide treatments, please contact the forest’s Invasive Plants Specialist: Jessi Brunson at 541-575-3067 or by email at

For further information, please contact:

Malheur National Forest, Supervisor Office at (541) 575-3000