2013 Forest invasive plant treatment program

Release Date: Apr 2, 2013  

Contact(s): Joani Bosworth (541) 278-3722

Pendleton:  The Umatilla National Forest will soon begin an integrated approach of prevention, manual, mechanical, herbicide, biological control and cultural treatments to reduce the risk of invasive species expanding on the forest.  This work will be implemented under the 2010 decision for the Invasive Species Treatment Project. 

Maps of the proposed treatment sites include:


Treatment on the forest is scheduled to begin in May and is expected to continue through October.  “The majority of herbicide treatments will be spot application to individual invasive plants using backpack sprayers and ATVs,” said Joan Frazee, Forest Botanist.  Some broadcast application is also planned along a small subset of roadsides. 


Herbicides to be used include clopyralid, picloram, glyphosate, metsulfuron methyl and chlorsulfuron.  “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 much reduced in size,” noted Frazee.  Herbicide treatments will be carried out following the project design features of the Record of Decision for the Invasive Plants Treatment Project. 


Invasive species have been shown to reduce biodiversity including wildlife habitat, wildlife and domestic livestock forage and streamside vegetation.  Invasive plants targeted for treatment include yellow starthistle, leafy spurge, spotted and diffuse knapweed, rush skeleton weed, meadow hawkweed, Scotch thistle, sulphur cinquefoil, dalmation toadflax, and houndstongue.   

Partners include County weed boards in Oregon and Washington, Oregon Department of Fish and Wildlife, Washington Department of Fish and Wildlife, Wallowa Resources, City of Ukiah, City of Granite, North Fork John Day Watershed Council, Oregon Department of Agriculture, Rocky Mountain Elk Foundation, Blue Mountain Elk Initiative, private landowners and ranchers.  Funding includes appropriated dollars and grant money from Title II projects, Rocky Mountain Elk Foundation and Blue Mountain Elk Initiative Challenge Cost Share projects.   

Treatment sites are located across the Umatilla National Forest and will be signed at the time of treatment.  For more specific information on timing and location of herbicide treatments, please contact the local Ranger District Office coordinators: 

  • Heppner Ranger District, Tim Collins - (541) 676-2114;
  • North Fork John Day Ranger District, Tom Thompson/Brad Lathrop - (541) 427-5365
  • Pomeroy Ranger District, Bill Lydie - (509) 843-4662
  • Walla Walla Ranger District, Carrie Spradlin - (509) 522-6059

For additional information contact Joan Frazee at (541) 278-3931.

-USDA is an Equal Opportunity Employer-