Do you know how many giant hogweed sites there are in King County? Or how many miles of river knotweed was controlled on last year? The 2016 Annual Report of the King County Noxious Weed Control Program has answers to these questions, and many more.

Read the report to learn how King County has been working collaboratively with residents, landowners, community groups, public agencies and others to reduce the impacts of invasive plants and noxious weeds on our quality of life, economy and the environment.

With a small, primarily seasonal staff, the Noxious Weed Control Program has been able to turn the tide on the spread of high priority toxic noxious weeds such as giant hogweed and reduce the rapid growth of invasive plants such as garlic mustard, orange hawkweed and purple loosestrife.

Giant hogweed is one of the most dangerous noxious weeds found in King County.

This snapshot of noxious weeds in King County highlights some of the regulated noxious weed species the program is targeting

Some of the program’s activities highlighted in the report include:

• Worked with 4,082 landowners and public agencies with state-regulated noxious weeds on their properties and achieved voluntary control of 96 percent of the infestations overall, including 99 percent of the infested county lands and roadsides.
• Surveyed 15 percent more area for Class A noxious weed garlic mustard than in 2015, protecting over 800 acres of forests and riversides from infestation.
• Surveyed 128 river miles for riparian weeds, assisted 1,700 property owners on rivers and controlled 175 acres of invasive knotweed.
• Reached over 10,000 residents through educational events.

This map highlights the King County rivers where the riparian noxious weed team targets knotweed

This table summarizes the vast amount of work done by the riparian noxious weed team with targets knotweed on rivers in King County.

The program’s success depends in large part on its ability to achieve strong cooperation and support of all stakeholders, including private citizens, governments, landowners, community groups and industry. Residents of King County have come to rely on the program as an important resource for assistance in their own efforts to combat noxious weeds.

If you have any questions about the report, please contact Steven Burke, Manager of the King County Noxious Weed Control Program in the Water and Land Resources Division of the Department of Natural Resources and Parks.