Weed Guide

This Weed Guide is designed to help you identify the worst of our area’s invasive weeds, and take steps to prevent, control and reduce them on whatever piece of the Methow you care for and want to steward.

Weeds. Some people say they are the single biggest threat to existing shrub-steppe habitat and successful land restoration. But what is a “weed” anyway? A simple answer might be “any plant that is growing where it’s not wanted.” Does that mean it’s bad? Not necessarily, in fact many weeds are edible, used medicinally and/or are sought after plants by native pollinators and honey bees. Additionally, some truly native plants can behave in a “weedy” manner. So, what’s the big fuss? The real issue is with “noxious” or “invasive” weeds, and we’ll use both terms synonymously in this weed guide. “Noxious weed” is the formal, legal term for invasive, non-native plants that are so aggressive and difficult to control that they harm our local ecosystems or disrupt agricultural production. These plants can out-compete native plants for sunlight, nutrients, and space; reduce habitat for wild and domestic animals; spoil rangelands and decrease agricultural production; poison animals; increase wild-fire risk; and reduce
recreational, scenic and property values. So while some weeds (and even natives) may be annoying (or “obnoxious”), noxious weeds are a genuine threat to our natural resources, ecology, scenery and even economy, and in many cases landowners are required under state law to control certain noxious weeds on their own property.

Click on a weed “card” below to learn more about a specific weed, and see the links on the right for more help, including local videos, a quick guide to common weeds, the weed control toolbox and more.

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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