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Lassen County SWAT tackles perennial pepperweed (Lepidium latifolium), with involvement from BLM, CDFA, Lassen County Agricultural Commissioner, and Pheasant’s Forever
Photo: Lassen County Agricultural Commissioner

One of the best ways to design successful invasive plant management is to study the successes and shortcomings of other projects. Below are some sample projects in the region, and a link to a database of project reports.

You may search for projects relating to any resource management topic in California in the Natural Resources Project Inventory database. Choose “exotic species” from the list of resource topics.

Weed Management Area Projects

These are examples of projects that have been undertaken in the region. To learn more about a particular project, contact the responsible WMA.

Butte WMA

Butte County weed mapping. Digital GIS maps of high priority weeds have been created by the Agricultural Commissioner’s Office for all rated weeds in the county with the goal of tracking weed presence and guiding management decisions. Species documented include Arundo donax, Japanese dodder, spotted knapweed and skeleton weed.

Arundo control at the Greylodge Wildlife Preserve. In a project funded by the California Department of Water Resources through the Sonoma Ecology Center, the WMA has chemically treated and burned Arundo on 20-24 net acres of the California Department of Fish and Game’s Greylodge Wildlife Area.

Purple loosestrife, Japanese dodder and yellow starthistle control. Butte WMA has used a variety of treatment methods to control invasive plants throughout the county. Purple loosestrife has been treated with herbicides and hand removal, yellow starthistle has been treated with biocontrols, and Japanese dodder has been treated with plant removal and chemical treatment of the roots.

Colusa, Glenn & Tehama WMA

Sites Reservoir purple starthistle treatment. The WMA, in partnership with Colusa and Glenn County Agriculture Departments, is working to protect 300 gross acres of grazing rangelands near Sites Reservoir in Colusa County. The project area has been chemically treated to remove purple starthistle.

Bear Creek arundo and tamarisk removal. One half mile of land along Bear Creek in Colusa County has been chemically treated for arundo and tamarisk to protect the riparian area. Plant material was removed after the chemical treatments. Project partners include Bureau of Land Management, Colusa County Resource Conservation District, CALFED Bay-Delta Program and University of California, Davis.

Lower Stony Creek arundo and tamarisk removal. Glenn County Resource Conservation District and a Landowner Advisory Committee made up of landowners and various agencies worked together to chemically treat 30 acres of arundo and tamarisk along Lower Stony Creek.

Perennial pepperweed and barbed goatgrass treatment. Two current projects include control and eradication of perennial pepperweed in Glenn County and early detection and eradication of barbed goatgrass in Tehama, Glenn and Colusa Counties.

El Dorado County Invasive Weed Management Group

Yellow starthistle leading edge project. El Dorado County Noxious Weed Management Group aims to prevent further spread of yellow starthistle (YST). The Sierra’s easternmost exposure to YST was determined by surveying, and further eastward encroachment is being prevented by mechanical removal and chemical treatment. A total of 500 acres of YST has been treated. Project partners include Eldorado National Forest, Sierra Pacific Industries, El Dorado County Department of Agriculture, private landowners, and the El Dorado Irrigation District.

Cleveland fire area spotted knapweed treatment. In order to protect threatened species in the Eldorado National Forest, a total of about 50 acres of spotted knapweed has been chemically treated by the WMA in the Cleveland Fire Area. Monitoring continues in the area, which will prevent further spread of spotted knapweed down the Silver Creek Tributary to the South Fork of the American River. Additional partners include Sierra Pacific Industries and the El Dorado County Department of Agriculture.

Perennial pepperweed and oblong spurge early detection and rapid response. The WMA is working with the El Dorado County Department of Agriculture, UC Cooperative Extension, private landowners, and contractors to prevent the spread of perennial pepperweed and oblong spurge in the Fairplay and El Dorado Hill areas of western El Dorado County. The weeds are spread easily in areas like these, which have new housing and road construction. The WMA will conduct surveys along 500 miles of roads to find extent of the infestation. They will disseminate information about Best Management Practices for preventing and eradicating the species through publications and at workshops for contractors, builders and landscapers.

Glenn County

For projects in Glenn County, see Colusa, Glenn & Tehama WMA above.

Lake WMA

Lake County arundo mapping and treatment. GPS technology was used to survey and create GIS maps for arundo and tamarisk species over 70-75% of Lake County. Of the mapped area, 60 % has been treated for arundo using two forms of chemical treatment. Most plants were originally treated using the cut-and-daub method, and then any re-growth was treated a second time by bending the plant down and spraying it with a dilute herbicide. Project partners included the East Lake and West Lake Resource Conservation Districts, Lake County Public Works, and the Agricultural Commissioner’s Office.

Broom grazing at the Robinson Rancheria. Broom species were grazed by goats on 1.5 acres at the Robinson Rancheria in Nice, on the northern end of Clear Lake. A follow-up treatment with clove oil on new shoots and re-growth during intense summer heat was very effective.

Lassen County Noxious Weed SWAT Team

Seasonal work crew project. The WMA was awarded a National Fish and Wildlife Foundation grant that, with the help of additional funding, has supported a two-person crew that works out of the BLM Eagle Lake Field Office. The crew spends the weed control season working with various organizations throughout Lassen County to aid a variety of weed control projects.

Lassen County tall whitetop removal. Throughout Lassen County, 64,000 acres of tall whitetop (aka perennial pepperweed) exist. In addition to wetlands, the plant occupies drier areas from roadsides to mountain tops. The Lassen County Noxious Weed SWAT Team used hand-pulling and herbicides to control tall whitetop along 7 miles of rivers. Many native plants returned to the control areas naturally, and some reseeding was done as well. Children from 4-H groups were involved as well, and they went to Washington, DC to learn more about tall whitetop and to educate others at a convention.

Carson wandering skipper protection project. Tall whitetop is being controlled and managed on 200 acres in the Amedee wetlands with the goal of protecting habitat for the Carson wandering skipper, Pseudocopaeodes eunus obscurus, an endangered butterfly. Project partners include the Bureau of Land Management, Natural Resources Conservation Service, Lassen County, Honey Lake RCD, Honey Lake Conservation Team, California Department of Fish and Game, and California Department of Food and Agriculture.

Modoc County MWA

Modoc County Scotch thistle control. The Agriculture Commissioner’s office worked with public lands agencies to control Scotch thistle with herbicides throughout Modoc County and in parts of northern Lassen County.

Surprise Valley noxious weed survey. The WMA, worked to survey and control 1,900 acres of noxious weeds in Surprise Valley. The targeted weeds, which include tall whitetop and yellow starthistle, were treated with herbicides. Project partners include Surprise Valley Resource Conservation District, Bureau of Land Management’s Surprise Field Office and the Fort Bidwell Reservation.

County A- and B-rated weed mapping. Dyer’s woad, tall whitetop, squarrose knapweed, Russian knapweed, Scotch thistle, Canada thistle, bull thistle and crupina were mapped using GPS/GIS throughout Modoc County. The maps have been used for strategic weed control planning. Project partners include North Cal-Neva Resource Conservation and Development, Inc., Modoc County Agriculture Department, U.S. Forest Service, Modoc National Forest, Bureau of Land Management Alturas Field Office, and the Central Modoc Resource Conservation District.

Nevada/Placer WMA

Interstate 80 corridor weed control. The Nevada/Placer WMA worked with PG & E, Placer County Agriculture Department, and many ski resorts to survey 3,204 acres of forested lands along I-80 from Colfax to Donner Summit. Spotted knapweed, tall whitetop and scotch thistle were documented, then treated with herbicides and removed by hand. Ski resorts involved include Soda Springs, Sugar Bowl, Donner Ski Ranch, Boreal, Alpine Meadows, Squaw Valley USA, Northstar at Tahoe, and Homewood.

Red Sesbania control in the American River watershed. In cooperation with the Sacramento WMA, the cities of Roseville and Rocklin, Placer County, and the Sacramento Area Flood Control Agency, the Nevada/Placer WMA controlled red sesbania along streams in the American River watershed. Treatment started in Loomis and continued downstream along Dry Creek and its tributaries. Treatment techniques included hand removal and cut-stump, and the original treatment will be followed by 5 years of follow-up monitoring and control.

Truckee Basin weed control. The Nevada County Department of Agriculture controlled musk thistle, knapweed species, short and tall whitetop, and yellow starthistle with herbicide treatments. The entire Truckee Basin from Donner Summit to the Nevada border has been treated.

Placer County

For projects in Placer County, see Nevada/Placer WMA above.

Plumas/Sierra WMA

Noxious weed roadside treatments. Roads throughout the WMA are mapped and treated for yellow starthistle, tall whitetop and Scotch broom. Some treatment also occurs on private lands. Treatment is primarily chemical, but some hand-pulling is done by the U.S. Forest Service along roads and in plots on FS land. CalTrans participates in the project by providing traffic control.

Cooperative cost-share program. The Plumas/Sierra WMA operates a cooperative cost-share program which provides herbicide at no cost to landowners, who use it to treat yellow starthistle and tall whitetop on their own lands. Herbicide was previously supplied to all interested landowners, and landowners of 5 acres or less may still participate in the cost-share.

Plumas/Sierra mapping program. The WMA continually maps all A-rated weeds throughout the two counties, and maps all C-rated weeds along roadsides. They use geographic software for mapping, and the data is stored in a format that may be converted to Arcview.

Sacramento WMA

Merten Ranch yellow starthistle control. 100 acres of yellow starthistle were treated using a helicopter herbicide application, in a cost-share between the owner of Merten Ranch and the Sacramento WMA.

Rossmoor Bar Restoration Project, American River Parkway. The WMA funded the purchase of weed removal tools like weed wrenches for weed removal work on the American River Parkway. Weeds like yellow starthistle, red sesbania, and arundo were mapped using GPS and aerial photos. A controlled burn for yellow starthistle was also carried out. The WMA worked with the Sacramento Weed Warriors to complete the project.

Noxious weeds outreach project. The WMA created brochures identifying the top 10 weeds in the county, in partnership with the Sacramento Agriculture Department, and with input from all organizations in the WMA.

Shasta WMA

Highway 299 broom removal. In partnership with PG&E, CalTrans, and Whiskeytown National Recreation Area, Shasta WMA treated invasive broom species along Highway 299. The project area has been maintained by numerous follow-up treatments.

Fall River perennial pepperweed treatment. In a continuing project, Shasta WMA is treating 1,200 acres of perennial pepperweed along Fall River, in eastern Shasta County. Project partners include PG&E, UC Cooperative Extension, and Shasta County Department of Agriculture.

Stillwater Creek Arundo removal. Shasta WMA has begun a new project, in partnership with the Western Shasta RCD, to remove Arundo donax (giant reed) along Stillwater Creek.

Sierra County

For projects in Sierra County, see Plumas/Sierra WMA, above.

Siskiyou WMA

Knapweed mapping and treatment in western Siskiyou County. In order to prevent the spread of knapweed species downstream, where agricultural lands could be impacted, or upslope to forests and rangeland, Siskiyou WMA treated populations of three knapweed species, reducing their density. Spotted, squarrose, and diffuse knapweed were mapped adjacent to U.S. Forest Service lands in the western part of the county using GPS/GIS, then mechanically or chemically treated. The acres infested by squarrose knapweed have been reduced from 1,600 acres to 30 acres. This reduction in density will prevent spread by vehicles, cattle, and mining equipment, which are vectors in this area. Project partners include U.S. Forest Service and Siskiyou County Department of Agriculture.

Eastern Siskiyou County perrenial pepperweed control. Perrenial pepperweed was chemically treated in the Tule Lake and Lower Klamath Federal Wildlife Refuges, in the eastern part of Siskiyou County. Treatments began at the outlying portions of infestations and worked their way towards the center of the infestations. Follow-up treatments are ongoing. Project partners include Tule Lake Irrigation District, the wildlife refuges, private ranchers and farmers, and Klamath County, Oregon.

Scott and Klamath River leafy spurge biocontrol. Siskiyou WMA partnered with California Department of Food and Agriculture, U.S. Forest Service, and Siskiyou County Department of Agriculture to control leafy spurge on Federal land along 60 miles of the Scott and Klamath Rivers. Two species of flea beetles and a longhorn beetle were used as biocontrol agents and were released at many sites along the rivers.

Musk and Scotch thistle treatment. Chemical and mechanical treatments were initiated on a project area of approximately 30,000 acres of Musk and Scotch thistle. Because it is so large, this site was originally designated as a containment and biological control site. The site is predominantly infested with musk thistle, but Scotch thistle has been increasing significantly. Siskiyou County Department of Agriculture partnered with Trinity National Forest to initiate the project and significant progress has been made.

Solano WMA

Yellow Starthistle Cost-Share. The Solano County Agriculture Department ran a cost-share program to split herbicide and labor costs 50/50 with farmers and ranchers. The program resulted in yellow starthistle treatment throughout the county.

Solano County Weed Mapping. Solano WMA used funding from the National Fish and Wildlife Foundation to map weeds on 400,000 acres throughout the county. The GIS maps, which detailed presence of yellow starthistle, purple starthistle, artichoke thistle, perennial pepperweed, and arundo, have been used to guide weed control efforts.

Arundo and Red Sesbania Control in the Sacramento River Delta. The WMA will partner with NRCS, Solano County and the U.S. Coast Guard to control arundo and red sesbania via herbicide applications. The project will use herbicides to control at least 20 net acres of the weeds along the Sacramento River Delta.

Sutter County

For projects in Sutter County, see Yuba/Sutter WMA below.

Tehama County

For projects in Tehama County, see Colusa, Glenn & Tehama WMA above.

Yolo WMA

Yolo County roadside noxious weed removal. Yolo WMA partnered with Yolo County Public Works and Yolo County Department of Agriculture to reduce noxious weeds by 99% along roadsides in the county. A total of 1,600 acres were treated using broadleaf herbicide treatments with the goal of converting the land to native grasses.

Perennial pepperweed and yellow starthistle treatment in Grasslands Park. With partners, Yolo County RCD, Yolo County Parks, and Yolo County Department of Agriculture, Yolo WMA reduced perennial pepperweed and yellow starthistle infestations by 99% on 320 acres. This protected threatened and endangered species in county open space.

Establishing native grasses. The WMA established many native grass plots along the Davis Bike Path, California Northern Railroad – CR99W, and Highways 113 and 505, with the goal of out-competing noxious weeds. Project partners included Caltrans, Yolo County Public Works, Yolo County RCD, Yolo County Department of Agriculture, and California Northern Railroad.

Yuba/Sutter WMA

Yuba County Fire Area yellow starthistle eradication. With project partners, Natural Resources Conservation Service and UC Cooperative Extension, the Yuba/Sutter WMA aerially reseeded 100 acres of land in Yuba County with non-invasive grasses to prevent invasive weed infestation. The project area was previously covered with yellow starthistle, and had recently burned.

Sutter County weed mapping project. In 2001, Sutter County created maps of weed presence throughout the county. The maps documented presence of Arundo donax and aquatic species, including parrotfeather.