Class A, B & C Weeds

The Washington State Noxious Weed Control Board (yes, there is such a thing) creates and maintains the state’s official list of noxious weeds, and they put the highly invasive weed species into three categories – Class A, B and C. From there, each county weed board personalizes the lists for its county. Only the worst weeds are classified but you still may want to prevent non-classified weeds from spreading on your land. Our Methow Weed Guide will specify if a weed has a class.

  • Class A noxious weeds are usually newcomers. They are often found in only a few places in the state, and state and local weed boards hope to completely eradicate them before they get a foothold in Washington. Class A weeds are the ones you are least likely to see – but the ones that are most important to report. (If you see a plant you think might be a Class A noxious weed, please report it to your county weed board.)
  • Class B noxious weeds are abundant in some areas of the state, but absent or rare in others. The state’s goal for Class B weeds is to control and reduce their occurrence where they are abundant, and to prevent them from spreading to parts of the state where they are rare or absent. The state or county weed boards often “require” people to prevent Class B weeds from spreading (by controlling/reducing them and/or by stopping seed production).
  • Class C Noxious weeds are already widespread in Washington and it is not considered feasible to require eradication. In Okanogan County, the weed board does not require control of these weeds, but tries to educate residents about why controlling them is a good idea.

For more information on the Washington State listing process and the weed list, click here.
To see the Okanogan County Noxious Weed Control Board Class A & B list, click here.

Puncturevine
The Seedhead

Puncturevine

Scientific Name: Tribulus terrestris

Puncturevine is an annual weed that sprouts and grows from seed every year and then dies. Starting from the central sprouting point at the root, stems spread out radially, staying low to the ground when the plant has direct sunlight. Dense mats can form with leaf-covered stems trailing out like runners, except the plant does not send roots from these stems. Mats start small and can grow quite large to several feet in diameter. In the shade, the same thing happens but the stems can grow slightly upright instead of flat to the ground.

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Tumble Mustard

Tumble Mustard

Scientific Name: Sisymbrium altissimum

Tumble mustard is widespread across the Methow, mostly in open, disturbed (or burned) sites such as roadside ditches, residential areas in the shrub-steppe, ranch and Ag land, and post-fire areas.


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Cheatgrass

Cheatgrass

Scientific Name: Bromus tectorum

Cheatgrass is probably the most common plant in the Columbia Basin, and it's one of the most widespread invasive (non-native) grasses in North America.

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Diffuse Knapweed

Diffuse Knapweed

Scientific Name: Centaurea diffusa


Diffuse knapweed is a biennial thistle that can mature and flower at a wide variety of heights - anywhere from a few inches to a few feet tall.


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Russian Thistle

Russian Thistle


Scientific Name:Salsola kali (also Salsola tragus and Salsola iberica)

Russian thistle is least noticed when it is young - slender, green and soft - and most noticed when it's a large, spiny, brown tumbleweed.

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Baby's Breath

Baby's Breath

Scientific Name: Gypsophila paniculata


Baby's breath is an easily recognizable addition to the Methow Valley's list of weedy plant species.


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Whitetop

Whitetop

Scientific Name: Cardaria draba


Whitetop is a perennial, which in this case is continually expanding downward and outward.

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