Forest Service continues effort to eliminate invasive plant populations from Tahoe Basin

Contact(s): Public Affairs, Lisa Herron 530-543-2815

[Image]: Forest Service Shield.SOUTH LAKE TAHOE, Calif. – The USDA Forest Service Lake Tahoe Basin Management Unit (LTBMU) will continue a project to eradicate, control, and contain known infestations of invasive plants in the Lake Tahoe Basin using chemical treatment. Work will take place at approximately 90 infestations sites (105 acres) beginning in late May and continuing through September 2019.

An Environmental Assessment released by the Forest Service in 2010, identified 493 known invasive plant infestation sites located on National Forest System lands managed by the LTBMU. Invasive plants reproduce and spread rapidly, displacing native plant species’ richness and diversity. Invasive plants can reduce the range and quality of fish and wildlife habitat, increase soil erosion and stream sedimentation, as well as impair recreational quality.

As of 2019, the LTBMU is managing as many as 723 separate invasive plant populations with 30 percent of those planned for treatment this year. While some invasive species like common St. John’s wort are managed by manually uprooting them, 40 percent of the 2019 priority populations will be treated chemically.

Current project areas include forested locations associated with hazardous tree thinning and fuels reduction on the West Shore of Lake Tahoe. Other possible locations include the Lam Watah area and the lower Truckee River corridor. In addition, invasive plant infestations on Forest Service urban lots may be treated.

Chemically targeted invasive plant species include Russian knapweed (Acroptilon repens), perennial pepperweed (Lepidium latifolium), Dalmatian toadflax (Linaria dalmatica var dalmatica), yellow toadflax (Linaria vulgaris), hoary cresses (Lepidium appelianum & L. draba) and Canada thistle (Cirsium arvense). Photos and information about these species can be found on the Lake Tahoe Basin Weed Coordinating Group’s website at

Treatments will include the use of three herbicides: Rodeo, Milestone, and Telar. Applicators will apply the product with backpack sprayers and other handheld tools with careful and direct application. Herbicide application will follow approved Environmental Protection Agency (EPA), state, and county direction.

Caution signs will be posted in treatment areas and will remain for at least 48 hours after treatment. Orange and black caution tape will mark the boundary around each treatment area and blue marker dye will be used to easily identify locations that have been sprayed. Treatment areas are very small, most consist of a few plants with the largest site less than five acres. Access to treatment sites will be restricted during and after application. 

For more information, contact Quinn Young at 530-543-2842 or visit


The mission of the U.S. Forest Service, part of the U.S. Department of Agriculture, is to sustain the health, diversity and productivity of the nation's forests and grasslands to meet the needs of present and future generations. The agency manages 193 million acres of public land, provides assistance to state and private landowners, and maintains the largest forestry research organization in the world. Public lands the Forest Service manages contribute more than $13 billion to the economy each year through visitor spending alone. Those same lands provide 20 percent of the nation's clean water supply, a value estimated at $7.2 billion per year. The agency has either a direct or indirect role in stewardship of about 80 percent of the 850 million forested acres within the U.S., of which 100 million acres are urban forests where most Americans live.

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