News and Upcoming Events

May's Weed of the Month - Tree of Heaven

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Tricky Beauty....Lesser celandine


Winter is over, now it's time for the native spring ephemeral wildflowers, those that grow, flower, and reproduce before the woodland trees leaf out. But some invasive plants prevent this from happening. One of these is Ranunculus ficaria, a.k.a. lesser celandine or fig buttercup. Now, you may be thinking "Oooh, pretty buttercups!" But, this plant has some nasty habits that are destroying native spring ephemeral wildflowers.

The leaves appear in late winter, forming a dense mat which prevents the growth of almost every other plant. You might be surprised to know this mat can even block out English ivy!

Lesser celandine, native to Europe, is a low-growing perennial plant. It was originally cultivated as an ornamental due to its attractive yellow flowers and ability to quickly create a uniform groundcover. Lesser celandine grows vigorously and forms large, dense patches in gardens and on forest floors, displacing native and ornamental plants. It can easily out-compete spring-flowering plant communities and negatively impact local wildlife. This invader emerges well in advance of most native plants and spreads rapidly via underground tubers and bulblets. The prolific tubers may spread to new sites through soil movement or be unearthed and scattered by humans and other animals. Mowing is not recommended as this spreads the plant through the bulbils on the stem. Lesser celandine is toxic to livestock and humans. It grows in full shade to full sun and prefers moist to wet soils but can persist in a wide range of conditions.

Early identification and timely removal of lesser celandine is crucial to preventing its spread. Due to its short life cycle, the window of opportunity for controlling lesser celandine is very short. Lesser celandine flowers in late winter before many other plants have started to grow. It's best to remove manually or with herbicide when all plants have come in for the season, just before or during its early flowering period (early spring). Lesser celandine is extremely hard to control once established. Utmost care should be taken not to move contaminated soil and plant parts should all be disposed of in the landfill to prevent contamination of the yard debris and compost system. Please do not share this plant!



April's Weed of the Month --- Italian arum

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More information can be found by visiting:


If you think you have Italian arum, please contact us for more
information on how to control it.  If you think you have seen
Italian arum in the wild, please contact our office to report the
location. Thank you!




Invasive Species Awareness Week

In conjunction with National Invasive Species Awareness Week and Washington Invasive Species Awareness Week, the Skamania County Board of Commissioners proclaimed February 24 - March 2, 2019 as Invasive Species Awareness Week in Skamania County! 

Check out the list of events happening all over the state to celebrate invasive species awareness week. 

People can take simple actions to help prevent the introduction and spread of noxious weeds and other invasive species by doing the following:

  • Before venturing outdoors, clean hiking boots, bikes, waders, boats and trailers, off-road vehicles and other gear to stop invasive species from hitching a ride to a new location. Visit the council's Washington Invasive Species Education (WISE) Web site to learn more about preventing spread.
  • Watch for noxious weeds. Visit the Washington State Noxious Weed Control Board's Web site to learn about noxious weeds. Residents who spot any in their yards or while walking in their neighborhoods, should notify the county noxious weed control board.
  • Dispose of unwanted pets, aquarium plants or water, science kits or live bait the proper way and NOT by dumping them into waterways. Released pets often suffer a slow death in winter, or may become invasive and damage other wildlife and agriculture. When it comes to unwanted pets or live bait, letting it loose is never the right thing to do. Visit the council's Don't Let It Loose Web page to learn the proper ways to dispose of unwanted pets and plants.
  • Campers should buy firewood where they'll burn it, or gather it on site when permitted. Don't move firewood from the local area where harvested. Visit the WISE Web site to learn about the potential dangers of moving firewood or the council's education campaign.
  • Enjoy catching salmon and steelhead? Protect them by not moving any fish from one waterbody into another. This will prevent the spread of fish diseases, while protecting salmon and steelhead fisheries from non-native predatory fish. Visit the Department of Fish and Wildlife's Web site to learn more about and restrictions around moving fish.
  • Become a Washington State University master gardener and help your community identify, report and properly manage exotic and invasive pests. Read details of the program.
  • Don't pack a pest. Certain items obtained abroad may contain invasive insects, viruses or weed seeds. When traveling abroad, review travel guidelines on items that should not be brought back to the United States.

Connect with us on Facebook!

The Skamania County Noxious Weed Program is now on facebook!  Find interesting articles about invasive species, native species, or share a photo of a plant you are having trouble identifying!  Connect with us @SkamaniaNoxiousWeedsflyer_Connect with us on Facebook

2019 Skamania County Noxious Weed List

On February 5, the Weed Board adopted the Skamania County Noxious Weed List for 2019.  The Weed Board has chosen to require control on all state listed noxious weeds in Skamania County.  Per RCW 17.10.140, landowners who have a Class A noxious weed on their property are required to eradicate that weed.  Landowners who have any Class B or Class C noxious weeds are required to control and prevent the spread of these species on an annual basis. 

If you think you may have a noxious weed on your property and need help identifying or managing weeds, please contact the Skamania County Noxious Weed Control Program.  We offer free home surveys and are happy to help form a plan to help you combat these invasive species. 

Best Management Practices

Best Management Practices for weeds affecting the Gorge, developed by the Columbia Gorge Cooperative Weed Management Area (CWMA) are now available!  View and download them here!

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NEWS RELEASE: Invasive Species Could Cost Washington Businesses, Agencies $1.3 Billion

News Release

For release: Jan. 12, 2017

Contact: Susan Zemek 360-902-3081 TTY 360-902-1996

Invasive Species Could Cost Washington Businesses, Agencies $1.3 Billion

OLYMPIA – A new report released today pegs the economic impact of 23 of the most damaging invasive species in Washington at $1.3 billion a year and a loss of 8,000 jobs, if there’s no prevention, according to the Washington Invasive Species Council.

“Invasive species are plants and animals not native to Washington, and once they land here, they out-compete existing wildlife,” said Justin Bush, executive coordinator of the Washington Invasive Species Council. “They can wipe out crops, clog waterways, damage pipes and dams and completely change the landscape and the wildlife that live there. Left unchecked, invasive species can ring up huge costs for control, kill jobs and harm our economy."

While there are more than 200 known invasive species found in or near Washington state, the economic analysis highlights the damages and potential impacts that could result if 23 of these species were allowed to spread in Washington in a single year.

Following are the total potential economic impacts of 23 invasive species on Washington’s industries:

Crops Cropland has the potential to be quickly infested by invasive plants, which require resources to control, and by invasive animals, which are looking for fruits and vegetables to eat. The total economic impact of the selected 23 invasive species on crops grown in Washington is estimated to be more than $589 million a year and 4,400 jobs lost.

Timber Many invasive species have the ability to severely impact Washington’s$1.68 billion timber and logging industry. Invasive noxious weed species such as Scotch broom can outcompete new saplings, which harms future timber harvests. Insect species such as gypsy moth have a more immediate impact on forests by defoliating and stressing adult trees, resulting in their death. The total economic impact of the selected 23 invasive species on the timber industry is estimated to be $297 million and 1,300 jobs lost.

Livestock Invasive noxious weeds in pastures and rangeland displace native plants eaten by livestock. In some cases, these plants also are poisonous to livestock and horses and can cause life-threatening ailments. The total economic impact of the selected 23 invasive species on the livestock industry is estimated to be more than $282 million annually and 1,500 jobs lost.

Recreation Recreational activities such as hunting, fishing and boating can all be adversely affected by invasive species. Many of the same species that impact a rancher’s ability to range their cattle also reduce elk and deer populations. Invasive species in the water hamper fish populations and can reduce access to popular fishing areas. Other water species can clog boat motors and render public boat launches unusable. The total economic impact of the selected 23 invasive species to recreational activities is estimated to be more than $47 million a year and 500 jobs lost.

Water Facilities Water facilities such as dams and irrigation systems can be devastated by aquatic invasive species such as Eurasian watermilfoil and quagga and zebra mussels. If invasive species are introduced to a facility, costly mitigation and maintenance systems must be installed for the facility to function. The total economic impact to water facilities from quagga and zebra mussels is estimated to be more than $100 million and 500 jobs lost.

The Worst Offenders

Rush skeletonweed, Scotch broom, apple maggot and zebra and quagga mussels are the most costly of the selected invasive species in Washington with an estimated total impact of more than $927 million and more than 5,140 jobs lost, the report concluded.

“Invasive species, including noxious weeds, affect all of us in Washington,” says Alison Halpern, the executive secretary of the Washington State Noxious Weed Control Board. “Many people have probably seen Scotch broom take over a vacant lot, knapweeds crowd out rangeland plants or Eurasian milfoil plug up a lake and make it hard to swim or boat. It’s important to understand that not only are they reducing native plant diversity and degrading important habitat, but they also can really hurt businesses that rely on Washington’s natural resources.”

Invasive species rapidly colonize new areas, displacing native species. Nationally, the impacts of invasive species and control efforts cost more than $137 billion annually but information on the specific costs of these impacts to Washington has been lacking.

To address the lack of information, the Washington Department of Agriculture, Washington State Noxious Weed Control Board and the Washington Invasive Species Council partnered with five other state agencies (Departments of Ecology, Fish and Wildlife, Natural Resources and Transportation, and the Washington State Parks and Recreation Commission) to hire Seattle-based Community Attributes Inc. to quantify the impact of 23 of the most damaging invasive species in Washington. The analysis gathered information on crops, livestock, timber and recreation such as hunting, fishing and boating.

“This economic damage can be reduced or even prevented by controlling noxious weeds, reporting invasive species, choosing non-invasive plants, never releasing unwanted pets into the wild and cleaning recreational equipment before and after use,” Bush said. “We all must do our part to prevent the introduction of invasive species to Washington state. With this amount of revenue and jobs on the line, we can’t afford to ignore this important issue.”

“As this report makes clear, invasive species can devastate the economy, in addition to our state’s environment,” said Jim Marra, pest program manager for the Washington State Department of Agriculture. “This is all the more reason for our agency and our partners to continue the invaluable work of preventing the introduction of invasive species to protect the state’s agricultural, environmental and other natural resources.”



Press Release


Natural Resources Building
P.O. Box 40917
Olympia, WA 98504‑0917


1111 Washington St. S.E.
Olympia, WA 98501









(360) 902-3000
TTY: (360) 902-1996
Fax: (360) 902-3026



Web site:

For release: August 8, 2016

Contact: Susan Zemek, 360-902-3081

 State Asks You to Check Trees for Invasive Forest Pests in August


OLYMPIA – Four state agencies and a university are asking residents to check trees in their yards for harmful bugs as part of the national Tree Check Month in August.

August is the peak time of year to find invasive bugs like Asian longhorned beetle, emerald ash borer and other aggressive wood-boring insects.

“Invasive insects can destroy Washington’s forests.” said Justin Bush, executive coordinator of the Washington Invasive Species Council. “In Washington, more than 22 million acres of forests are at risk from invasive insects and disease. We need everyone’s assistance to prevent these damages in Washington State.”

The Washington Invasive Species Council, Washington State Department of Agriculture, Washington State Department of Natural Resources, and Washington State University Extension are asking residents to take ten minutes to go outside and inspect their trees. Invasive wood boring insects typically emerge from trees in August. Experts also suggests that all pool owners should check their pool skimmers and filters for the invasive bugs. Emerging adult insects often end up as debris collected in pool filters.

If residents see any invasive insects or signs, they should to take photographs and report the find immediately at, where they can get an online reporting form or download the free WA Invasives mobile app.

“Initial infestations are difficult to detect, so early detection and reporting is critical to rapidly manage new populations,” Bush said. “Our state needs help finding new outbreaks so they can be contained quickly and eliminated.”

“Early detection and rapid response is the more effective and cost-efficient approach to managing new invasive species, whether because we have the opportunity to eradicate it or because we can take steps to quickly limit their impact,” said Dr. Chris Looney of the Washington State Department of Agriculture. “Our own data show that the general public is an important source of first detections.”

First indications of invasive insect damage to trees include sudden die back or death among a group of like trees that are otherwise vigorous and healthy. If you see this, investigate further and look for sawdust, exit holes or actual beetles. You might help find one of these invasive species:

  • The Asian longhorned beetle is a large shiny black beetle with white spots. At this time of the year, adult beetles emerge from trees leaving large, circular exit holes about 3/8 inch in diameter. These beetles feed on many species, but maples are one of their favorites. Washington has a number of look-alike native beetles and it takes a trained eye to distinguish them, so residents are asked to provide any suspect beetles to one of the agencies mentioned above. If you see numerous shallow holes arranged in rows, this could be the result of sapsucker feeding and not a serious concern. More details on signs and symptoms can be found at
  • The Emerald ash borer is a shiny, half-inch long, green metallic beetle. Adults begin flying in June and will continue through August as they emerge from ash trees, their primary host. Exit holes are about a quarter-inch wide and have a distinctive D-shape. A potential sign of an infested ash tree is heavy wood pecker feeding activity, as they search for larvae by removing the outer bark. More information can be found at

Need help recognizing suspicious beetles?

“Each county has a WSU Extension Office and Master Gardener Program that can help identify suspect beetles,” said Todd Murray, director for Washington State University Extension Agriculture and Natural Resource Unit. “And if they can’t, they know the specialist to send it to. Master Gardeners are often the first ones to recognize and report a newly introduced insect pest. Master Gardener clinics receive a large number of insect samples at this time of year.”

“When it comes to the health of your trees, a few minutes checking them for insects can make a big difference,” Bush said.

For more information about invasive species, and ways to keep them from spreading, visit and



1. Asian longhorned beetle (Anoplophora glabripennis)
Image Credit: Michael Bohne,

Image Link:

2. emerald ash borer (Agrilus planipennis)
Image Credit: Debbie Miller, USDA Forest Service,
Image Link:


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