Snoqualmie Valley forests at risk as patch of noxious weed garlic mustard found

King County Noxious Weed Program works to eradicate invasive plant infestation

The recent discovery of garlic mustard in the Snoqualmie Valley has put the King County Noxious Weed Program on high alert.

The plant, which out-competes native vegetation and depletes soil nutrients, is growing on several adjacent properties in North Bend near a creek that drains into the South Fork Snoqualmie River.  This is the first confirmed infestation of garlic mustard in the agriculturally important Snoqualmie Valley.

Sasha Shaw, noxious weed specialist with the King County Water and Land Resources Division, said it’s possible the plants could have been introduced to the area in some gravel dropped recently by a visitor from the Midwest.

“This forest invader is already a widespread problem across much of the eastern and midwestern United States, and it is on the move in the Pacific Northwest,” Shaw said.

“We urge area residents to contact the Noxious Weed Program if they think they’ve found garlic mustard on their property or in their neighborhood. Early detection and a quick response are our best weapons in battling this weed, and it helps us locate potential additional infestations.”

Garlic mustard is challenging to identify and resembles many other plants. Shaw said citizens can visit the Noxious Weed Program Web site, www.kingcounty.gov/weeds, to see photos and descriptions of the plant, or call 206-296-0290.

Garlic mustard is one of 48 state-listed noxious weeds that the King County Noxious Weed Program is working actively with landowners to control.  Noxious weeds are non-native plants introduced to Washington that cause damage to the natural or economic resources of the state.

Garlic mustard is an example of a Class A noxious weed – the highest priority for eradication – due to its potential to invade and damage forests throughout the Pacific Northwest.

“King County has a great opportunity to prevent widespread habitat degradation with a rapid, coordinated response to noxious weeds like garlic mustard,” said Noxious Weed Program Manager Steven Burke. “By acting quickly and decisively, and coordinating with landowners and other agencies, we can succeed in preventing new invasions before they get out of control.”

King County Noxious Weed Program staff and the City of Bellevue are currently battling a newly discovered large garlic mustard weed infestation on land that’s bordering the county’s Cougar Mountain Regional Wildland Park.  Weed program staff have also been working closely with the City of Seattle and Seattle homeowners for several years to battle garlic mustard infesting several city parks and roadways and dozens of private properties.

Related information

Garlic mustard identification and control

Agriculture in King County, Washington

Northwest natural yard and garden

King County Water and Land Resources