King County Noxious Weed Board meets Jan. 16 to discuss weed control list

County panel mulls changes to weed list as state requires control of 5 new weeds

Knowing which weeds will crop up to cause headaches for King County landowners is anybody's guess, but it's a sure thing that the county's noxious weed list is about to have a growth spurt.

European hawkweed and common cordgrass are among the four "Class A" weeds that will be added to the list of weeds county agencies and landowners are required to control when the King County Noxious Weed Board meets Jan. 16 at the Mercer Island Library. The meeting is set for 4-6 p.m. at the library, 4400 88th Ave SE in Mercer Island.

The County Weed Board may also consider proposals to require control of additional state-listed weeds and to add weeds to the voluntary "Weeds of Concern" list.

Noxious weeds are non-native plants introduced to Washington that damage natural and agricultural resources or human health. They are highly aggressive and difficult to control.

"King County recognizes the serious threat that invasive species pose to the county's resources and strives to use every tool available to prevent new infestations and reduce the impact of existing noxious weeds," said Steve Burke, a manager with King County's Noxious Weed Program.

To help protect the state's resources, the Washington State Noxious Weed Control Board adopts a statewide noxious weed list each year. Each county's weed board then adopts a county noxious weed list that establishes which weeds require control by property owners and public agencies.

The county is required to include all state-listed Class A weeds and any Class B weeds designated for the county by the state, and may select additional state-listed weeds for required control in the county.

The county's noxious weed list places a priority on preventing new infestations of the most serious noxious weeds, and encourages property owners to work together in stopping the spread of established noxious weeds.

Of the four new Class A weeds, only one is known to occur in King County. European hawkweed (Hieracium sabaudum) is an aggressively spreading, yellow-flowered perennial similar to other hawkweeds already on the list that is just starting to spread into Washington. King County's current populations of European hawkweed are mostly on state highways.

Another new Class A weed is common cordgrass (Spartina anglica), which was previously found on Vashon Island but seems to have been eradicated from that location. This species was moved up from Class B status because of the successful eradication program in Puget Sound.

The other new Class A weeds are ricefield bulrush (Schoenoplectus mucronatus) and variable-leaf milfoil (Myriophyllum heterophyllum), neither of which has been found in King County.

The only other new weed required for control by the State Weed Board is common reed (Phragmites australis), a tall, dominating grass in wetlands and shorelines that is fairly limited in distribution in King County.

This weed was upgraded from Class C to Class B. However, property owners and public agencies were already required to control this species in King County, due to the County Weed Board's selection of this species in previous years. This wetland grass is a serious threat to wildlife and native plant habitat and is proving to be very difficult to eradicate once it is established.

In addition to reviewing the changes made by the State Weed Board, the County Weed Board may select additional weeds from the state weed list for required control in the county.

The County Board will consider renewing the countywide required control of tansy ragwort (Senecio jacobaea), hairy willowherb (Epilobium hirsutum), common hawkweed (Hieracium lachenalii), and all unspecificed non-native invasive hawkweeds (Hieracium sp.).

The panel will also consider continuing to require countywide control of purple loosestrife (Lythrum salicaria) and garden loosestrife (Lysimachia vulgaris). Information on these and other noxious weeds on the county list can be found online at www.kingcounty.gov/weeds.

For more information on the King County Noxious Weed Board and the upcoming public meeting on the county weed list, call or e-mail Burke for more information at 206-205-6927 or steve-j.burke@kingcounty.gov.

For more information on these new weeds and other changes to the state weed list, visit the State Weed Board Web site: http://www.nwcb.wa.gov/index.htm or contact Alison Halpern at the State Weed Board at 360-902-2082 or noxiousweeds@agr.wa.gov.