Posts Tagged: Cheryl Wilen

UC launches WeedCUT, a new online tool to manage invasive weeds in wildlands without herbicides

California has abundant wildlands — forests, rangeland, open areas, wildlife refuges and national, state, and local parks — that need protection from invasive plants. Invasive plants affect all Californians by increasing wildfire potential; reducing water resources; accelerating erosion and flooding; threatening wildlife; degrading range, crop and timberland; and diminishing outdoor recreation opportunities. According to the California Invasive Plant Council (Cal-IPC), more than 200 identified plant species harm California's wildlands.

Cal-IPC and the University of California Statewide Integrated Pest Management Program (UC IPM), with funding from the California Department of Pesticide Regulation (DPR) Alliance Grants Program, developed two resources that provide land managers access to the latest information on non-herbicide practices for managing weeds in wildlands. Best Management Practices for Non-Chemical Weed Control is a free downloadable manual. The same information has been incorporated into an interactive online tool called WeedCUT (Weed Control User Tool: weedcut.ipm.ucanr.edu).

"We anticipate WeedCUT will increase the use of more mechanical, physical, or biological practices, and potentially result in the reduction of herbicides used to manage wildland invasive weeds," said area IPM advisor emeritus Cheryl Wilen. "Best Management Practices for Non-Chemical Weed Control and WeedCUT were developed so land managers can become more knowledgeable and skilled in the use of non-herbicide methods as part of an IPM program.”

Best Management Practices for Non-Chemical Weed Control provides comprehensive descriptions of 21 commonly used non-herbicide weed control techniques and biological control agents for 18 invasive plants. Each chapter is the synthesis of research and on-the-ground knowledge from practitioners about non-herbicide methods. The chapters describe how a technique is best applied, the types of invasive plants and environmental conditions where it is most effective, and what its shortfalls might be. Environmental, cultural, and human safety risks are highlighted to help support the safe and effective use of these methods.

WeedCUT is the online version and can be used to learn about the different non-herbicide management methods, including the section on biological control. To filter through the database and learn which management practice to consider for a particular site and invasive plant type, a simple interface allows users to pick characteristics that describe their site and invasive plant problem. The tool then filters through the database to display the practices ranked by efficacy (excellent, good, fair, poor or ineffective). As in the manual, use of the technique and potential hazards are covered.

Best Management Practices for Non-Chemical Weed Control and WeedCUT are designed to be the go-to resources for practitioners that complement their conventional weed management work with non-herbicide techniques or are restricted in their use of herbicides. Both resources will help practitioners manage weeds more effectively.

“Many experts in the field have contributed to create the manual and WeedCUT. It has been exciting to see these techniques described and reviewed so carefully. We're looking forward to seeing land managers, as well as all folks fighting weeds, incorporating the information from the manual and WeedCUT into their work,” said Jutta Burger, science program director and project lead with Cal-IPC.

While the manual and tool focus on non-herbicide methods, the hope is future funding can be found to continue the work and integrate herbicide options online.

"Land managers typically use both herbicide and non-herbicide methods, alone and in combination, to manage invasive plants in wildlands," said UC Cooperative Extension advisor and UC IPM-affiliated advisor Tom Getts. "A tool that combined both herbicide and non-herbicide methods would guide land managers to determine the most effective overall management program for their particular site." 

Control garden weeds in early spring

Weeds are easiest to control when they are tiny emerging plants, reported Jeanette Marantos in a Los Angeles Times blog post. Marantos got tips on weed management from Cheryl Wilen, UC Cooperative Extension integrated pest management advisor in Southern California.

Wilen recommends home gardeners use a swivel (or hula) hoe to scrape the surface and decapitate weeds. “It's a bit of exercise,” she said, "but you can do it so quickly, it's not a problem.”

Another weed control strategy is a thick layer of mulch, with does double-duty by reducing water evaporation from the soil surface, thereby conserving water. Wilen suggests a three- to four-inch layer of mulch be spread in garden beds and landscape borders before the weed seeds have a chance to germinate. Mulch  blocks the sunlight weeds need to push through the ground.

Fabric weed barriers are useful for controlling particularly challenging weeds, like nutsedge. Wilen suggests covering the fabric with mulch for an esthetically pleasing weed-free garden.

Though the common herbicide glyphosate (such as Roundup) kills weeds and is safe if used correctly, Wilen prefers using the swivel hoe.  "It's just quicker and easier than pulling out the spray equipment," she said.

Invasive weeds are taking a toll on wildflower displays

Sahara mustard, a resilient weed native to North Africa and the Mediterranean, is invading desert landscapes in the American Southwest, squeezing out beautiful wildflower displays that attract tourists and maintain the local ecology, reported the San Diego Union Tribune.

UC Cooperative Extension is testing methods of removing Sahara mustard, including hand weeding, hoes and herbicide. But these are only stopgap measures meant to keep the plant at bay in select spots.

“I don’t think we’re ever going to spray the herbicide across the entire Southwest,” said Chris McDonald, UCCE advisor in San Bernardino County. “But the idea is preserving areas of value, such as the wildflower fields of Borrego Springs.”

Sahara mustard has been in California since 1927, but it wasn't until Hurricane Kathleen doused California in 1976 that it proliferated widely, according to Rich Minnich, professor in the Department of Geography at UC Riverside.

“There was this gigantic explosion of mustard, and it’s never been the same since,” Minnich said.

Anza-Borrego's tough eradication project: Cutting the mustard
Louis Sahagun, Los Angeles Times

A front-page story in the Los Angeles Times detailed the changing attractions in Borrego Springs. Tourists used to come to see a colorful display of wildflowers, but because of an invasive weed, Sahara mustard, local officials are now trying to turn visitors attention to hiking, cycling, star gazing and photography instead. UCCE's Chris McDonald, who is conducting research on Sahara mustard control, was featured in four of the nine photos that accompanied the story.

Nutgrass: Three experts' solutions to one of the worst weeds
L.A. at Home blog, Los Angeles Times

Nutsedge is commonly considered a gardeners' worst enemy, which is further proven by the draconian measures to control the weed offered by UC and other experts in the L.A. at Home blog this week. In the introduction to the problem, Cheryl Wilen, UC Cooperative Extension advisor, notes there are two kinds of nutsedge. One way to tell them apart takes a little courage.

"If you are inclined to bite into one," she said, "yellow nutsedge has a pleasant almond or brazilnut taste, while purple nutsedge does not have a good flavor."

Controlling either kind is challenging. Yvonne Savio, UCCE manager of the L.A. County common ground program, suggests extricating the weed in a way that may seem extreme.

Dig 6 inches around and under each weed and throw the weed and dug up soil into the garbage. "Don't even think of composting the weed or filtering the soil through a screen," Savio said. The weeds will come back.

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