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Noxious weeds

King County, Washington

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Weeds in the news

Weeds sometimes make it to the press. Below are some of the recent (and some of the timeless) news items related to invasive plants.


King County urges landowners to watch for deadly noxious weeds this spring, King County Press Release. April 2, 2015

King County’s noxious weed list has growth spurt with addition of 4 new garden escapees, King County Press Release. Jan 8, 2015.  


Study suggests that climate change will make wetlands more vulnerable to invasive species:

A story from California about how big a management problem water hyacinth can be when it gets established:

Australia tries out invasive plant sniffing dogs:

Possible new tool in fight against cheatgrass in the intermountain west:

A sad Christmas tree story for some shoppers in Hawaii and a cautionary tale about not checking for hitchhikers before transporting materials:

Chinese botanists find that over 500 invasive plants have taken root in China, over half of which are from North and South America, including our local native goldenrod:

Play Clean Go.  The Nelson Daily, 8/17/2014. We all need to remember this as we recreate in the wild this summer – please don’t take unwanted hitchhikers on gear and clothes.

Wayne’s World: Attack of the giant hogweed plant, it’s no joke. Hudson Valley’s, 8/17/2014.  A reminder to watch for this huge garden escapee, and also to avoid introducing a new species without doing your research.

Gardening: Pitch the Lythrum and plant something better.  Pittsburgh Post-Gazette, 8/16/2014.  An excellent gardener’s perspective on why we should not plant purple loosestrife in our gardens in spite of the undeniable attractiveness.  Thank you Carol Papas!

City of Bainbridge Island approves herbicide use to fight noxious weeds.  Bainbridge Island Review, 8/16/2014. The city decided that keeping noxious weeds controlled along public roadways is a crisis that must be addressed.

Weed control on rangeland, part III.  Hays Daily News, 8/16/2014 and Weed control on rangeland, part II, Hays Daily News, 8/7/2014.  These articles look at the cost-benefit ratio of spot-spraying target weed species versus spraying all broadleaf plants in rangeland.  Does cattle productivity really go up with more grass and fewer broadleaf plants?  They make sure to differentiate between noxious weeds and non-invasive weeds (otherwise known as “plants”).

Getting more bang for your buck with herbicides. Post and Courier, 8/16/2014.  This article is not an endorsement of herbicide use, but rather it is an excellent summary of basic good practices if you do choose to use herbicides to control weeds.  Remember, the label is the law and it also tells you how to use the product so it will work best.

Invasive trees being treated in West Valley., 8/15/2014.  Crack willow, or Salix fragilis, is a non-native willow species that Yakima County is trying to get a handle on.  This is a species I definitely need to learn more about. 

Researchers investigate invasive plants., 8/10/2014.  Investigators are looking at whether native or invasive plants are benefiting more from climate change in Alaska.  Although the results aren’t in yet, it’s great that the research is being done.

Beware of the Giant Hogweed, the invasive plant that can cause burns and blisters. May 12, 2014 

City People's Garden Store first in King County to commit not to sell invasive plants, noxious weeds. King County/City of Seattle Press Release. April 9, 2014.

Climate change and noxious weeds. New research sheds some light on how climate change will affect noxious weeds (hint, the weeds will be happy).  See High Plains Public Radio and All Things Considered for a research project involving the impacts of increased carbon.  See the December 2013 Smithsonian Magazine for a different research project, and a news story about research showing that invasive plants in the waterways of Ireland will likely benefit from climate change.

New DNA tool helps distinguish invasive and native aquatic plants.  A USGS News Release describes how this tool helped pin down when non-native hydrilla was first found in the Potomac River.

Spartina control in the San Francisco Bay Area turns a corner.  A recent story in BayNature describes the painstaking process of restoring the native spartina while eradicating the non-native species and hybrid without harming the endangered clapper rail.

Lesser celandine alert in the news.  The Bellingham Herald raises awareness about the new Washington State Class B noxious weed lesser celandine, also known as ‘Brazen Hussy’ among other names.

Pesticides and bees. There is a new resource available on how to reduce bee poisoning from pesticides, especially certain insecticides that pose the greatest risk.  The information is summarized in the PNW Insect Management Handbook or you can download the complete publication, How to Reduce Bee Poisoning from Pesticides (PNW 591) (Search for “PNW 591”).

April news wouldn’t be complete without one story like this.  See this HCN Story on a supposed big new invasive animal problem in the west.


The story of clematis:  Guest column Islands' Sounder, December 19, 2013

Noxious Weed Control Board meets Jan. 15 to determine 2014 King County noxious weed list. King County Press Release. December 16, 2013.

How Climate Change is Helping Invasive Species Take Over. Smithsonian, December 2013.
Invasive plants blooming earlier with climate change

Bay Researchers Fight Uphill Battle with Invasive Cordgrass. BayNature, November 21, 2013.
Article outlining the history and Work on controlling Spartina in California by the Invasive Spartina Project. They are working to control Spartina alterniflora and also a hybrid of S. alterniflora with a native species, California cordgrass, S. foliosa. This hybrid has been tough to eradicate.

Reducing Milk Thistle to Zero Density. TechLine Invasive Plant News, September 9, 2013. 
Article in Techline news about milk thistle control efforts on Catalina Islands and their new approach to control with includes early fall applications of Milestone herbicide at 6 fluid ounces per acre (fl oz/A).

Microbes Facilitate the Persistence, Spread of Invasive Plant Species by Changing Soil Chemistry
Sep. 26, 2013 -- Invasive species are among the world's greatest threats to native species and biodiversity. Once invasive plants become established, they can alter soil chemistry and shift nutrient cycling in an ecosystem. This can have important impacts not only on plant composition, diversity, and succession within a community, but also in the cycling of critical elements like carbon and nitrogen on a larger, potentially even global, scale.

Noxious weed alert - Thistle (from San Juan County, Ed note: removed link as of 8/7/2014)
Thistles are common, recognizable weeds in the San Juan Islands, yet there are several thistles that are native to the US, one of which is located in the county. Our local native is known as Indian, short-style or clustered thistle (Cirsium brevistylum) and can be confused with bull thistle (C. vulgare). (See the link above for the full article).

Hunting? Don't Spread Noxious Weeds in Idaho's Backcountry
Sep. 26, 2013 -- During Idaho’s hunting seasons, thousands of people traverse Idaho’s backcountry. So the threat of spreading noxious weed seeds from infested areas is at a high level, state weed officials warned.

Spartina control in British Columbia gets a boost from Washington’s Spartina program
August 22, 2013 – The WSDA Spartina crew was up in British Columbia this summer, helping to treat spartina populations. This is the first time aquatic herbicide applications have been used in Canada.  Washington has made excellent progress in combating spartina and controlling populations up north will greatly help Washington’s effort to eradicate this tough noxious weed from the beaches and mudflats of Puget Sound and Washington’s coast (see the link above for the video).

Soil scientist suggests fallow tillage to organic farmers
August 21, 2013 -- A soil scientist at Cornell University suggests organic farmers use tillage to control weeds without sacrificing their soil structure. Charles L. Mohler, senior research associate at Cornell's Department of Crop and Soil Sciences, described a technique of fallow tillage as part of a crop rotation approach.

Prehistoric Europeans spiced their cooking (with garlic mustard)
August 21, 2013 -- Europeans had a taste for spicy food at least 6,000 years ago, it seems.  Researchers found evidence for garlic mustard in the residues left on ancient pottery shards discovered in what is now Denmark and Germany. (See link above for the full article).

King County sounding the alarm as harmful weeds begin to grow this spring. King County Press Release. April 2, 2013.

Plant wars kick in when dams come out. Great Lakes Echo. March 8, 2013.
Vegetation management is needed to avoid letting invasive plants get a jump on native plants in midwestern dam removal projects.

Invasive species hitchhiking to west coast on Tsunami debris. Times Colonist. March 8, 2013. 
Concerns about tracking invasive species coming to BC, Washington and Oregon coasts from the 2011 tsunami in Japan.

Invading Species Can Extinguish Native Plants Despite Recent Reports to the Contrary. Science News, January 9, 2013.
Ecologists at the University of Toronto and the Swiss Federal Institute of Technology Zurich (ETH Zurich) have found that, given time, invading exotic plants will likely eliminate native plants growing in the wild despite recent reports to the contrary.


Aggressive ground covers may really be invasive weeds. Oregon, September 13, 2012.
Be careful what you plant: here’s a look at some groundcovers that are invasive and very hard to get rid of.

Meet Seattle’s Newest Invasive Plant. A garlic mustard infestation poses serious threats - and it will cost you. Seattle Magazine, August 2012.
Seattle Magazine writer Roddy Scheer writes about his experiences with garlic mustard and the King County Noxious Weed Program.

Concrete-busting weed can threaten projects. Journal of Commerce, August 29, 2012.
Knotweed catches the attention of the construction industry in British Columbia (and should here as well).

Help stop invasive plants species [in British Columbia] with new app. Kamloops The Daily News, August 24, 2012.
Reporting invasive weeds just got a lot easier in British Columbia with the new Report-a-Weed smart phone app for reporting weeds anywhere in the province.

Nasty alien weeds a growing threat in populated corners of Alaska. Alaska Dispatch, July 10, 2012.
A humorous and sobering view on invasive plants in Alaska from former Alaska Department of Fish and Game wildlife biologist Rick Sinnott.

King County Targets 3 New Invasive Plants. King County DNRP Press Release. March 20, 2012.
County offers free workshops to teach residents and agencies what to look for and how to control noxious and invasive weeds.

Forest Service has a weed problem in wilderness. March 19, 2012.
Infestations have been discovered in seven wilderness areas in the Mount Baker-Snoqualmie National Forest.  Public comments are being accepted until April 2 on the Forest Service weed eradication options for these sites.

Revised Aquatic Noxious Weed Permit issued by Department of Ecology. Mason County Daily News. February 3, 2012.
The State's revised permit is in effect for anyone controlling noxious weeds with herbicides near water.

UCSB Scientists Warn Against Invasive Species. Daily Nexus. January 31, 2012.
A recent study led by scientists at UC Santa Barbara.s National Center for Ecological Analysis and Synthesis demonstrated how globalization and the demand for drought-resistant plant species threaten to overcome native plants in the United States. Based on these findings, the scientists proposed that bio-imports be screened before entering the U.S.

State revises permit covering treatment of aquatic noxious weeds. Washington Department of Ecology Press Release. Janaury 23, 2012.
The Washington Department of Ecology has revised a permit that protects people and the environment when herbicides are used to curb the spread of noxious weeds growing in wet areas.

Peg Tillery: Knock out knotweed now.  Kitsap Sun. January 31, 2012.
This columnist reminds us to get the ball rolling on knotweed control plans for the year.

Cattle can be trained to eat weeds, control noxious growth in pastures.  Prairie Star. January 4, 2012.
There has been success so far with a pilot program in Montana where cattle were trained to eat Canada thistle. The cattle ate enough of the plants to prevent them from going to seed. In other mentioned cases, cattle also ate musk thistle and spotted knapweed.


  • Lake Oswego council takes a whack at invasive trees.  Portland Tribune. December 22, 2011.
    Oregon’s Lake Oswego’s city council has a new permit process that hopes to encourage the removal of invasive trees. Before, residents had to pay permit fees to remove these trees, now they can get a permit in a free, expedited process.

  • Danger of dumping yard waste in natural areas. Woodinville Patch. Novermber 9, 2011.
    This article explains how weeds can spread from yard waste and the problems invasive weeds cause in forests and parks.

  • Battle returns to Black Lake weeds. Chinook Observer. November 8, 2011.
    This article talks about spraying Brazilian elodea in Black Lake, Ilwaco WA. It also includes information about a student group that has been taking water samples to help monitor the lake during the Brazilian elodea control.

  • Board classifies perplexing invader as noxious weed. OPB News. November 3, 2011.
    The Washington State Noxious Weed Board adds Japanese eelgrass to the noxious weed list to help commercial shellfish growers obtain permission to control it.

  • Blackberry's deeply rooted history ends with an ironic twist.  Times Colonist. November 2, 2011.
    This article tells the story of how Luther Burbank discovered Himalayan blackberry and successfully promoted it to commercial growers in North America after a slow start, unfortunately followed by the rapid spread of this plant well beyond where it was planted.








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Program offices are located at 201 S. Jackson St., Suite 600, Seattle, WA 98104. To contact staff, see the Noxious Weed Control Program Directory, send an email, or call 206-477-WEED (206-477-9333).