Frequently Asked Questions

Noxious weeds are non-native plants that have been introduced accidentally or as ornamentals in peoples' gardens. Some are poisonous to humans and livestock and most grow rapidly and are extremely difficult to control. They can reduce crop yields, displace desirable plant species, destroy beneficial native habitat, damage recreational opportunities, clog waterways, and diminish land values.

In 1998 the Metropolitan King County Council authorized the first small special assessment on each property tax bill to fund the weed control program. The Council passed Ordinance No. 14263 in November of 2001 authorizing a special assessment of $1.50 plus $0.09 per acre per year for each property parcel. As authorized by state law, more than 16 Washington counties now have noxious weed assessments on their property tax bills so weed programs can have a dedicated source of funding.

A state law passed in 1969 mandates all counties to have a program to combat noxious weeds. King County was under court order to operate a weed control program as result of a 1995 lawsuit by the State of Washington. The suit was prompted by complaints from neighboring counties that King County was not controlling noxious weeds as required by state law.

The King County Noxious Weed Control Board was established to direct the state mandated program as required by the court order. The board consists of five unpaid citizen volunteers who represent five districts that cover the entire county. The board meets monthly and provides vision and direction to the weed control program. While the program staff are technically county employees, they are hired, directed and supervised by the citizen board.

The King County Noxious Weed Control Program focuses on education, prevention, technical assistance and control of noxious weeds through voluntary compliance. Preventing the spread of weeds is more effective and less costly than eradication.

During the months of April through September, when weeds are growing the most rapidly, the program employs field staff members with scientific backgrounds to survey public and privately owned lands in King County for noxious weeds and to work with landowners to achieve weed control. The survey staff rarely enter private property without the owner's express permission. In fact, about half of our work comes from citizens reporting infestations and asking for information and assistance in getting rid of noxious weeds on their own property. The remainder of the infestations are sighted by the program's field staff as they travel the county.

Once an infestation is identified, the landowner is given a variety of options, including hand pulling, mowing or cutting; advice on better pasture management; and using the most effective and least harmful methods of applying herbicides. The King County Noxious Weed Control Board does not require people to use herbicides to control weeds.

The majority of weed infestations are controlled voluntarily by landowners. Less than 1 percent of the known weed infestations are controlled by the weed program and, as authorized by state law, the landowners are billed.

Weeds are everyone's problem. Even landowners who don't currently have weeds can be harmed by weeds that spread from adjacent lands. Seeds are carried by wind and cars and the invasive nature of these plants means that no land is immune to their spread. Prevention of new infestations and introductions is a top priority of the weed board.

When the state passed the law mandating that counties control noxious weeds, it gave counties only two ways to fund the work. They can either use general fund money, for which there is a lot of competition, or they can assess a special dedicated fee on property. It is not a tax, it is a regulatory fee for a service that is available to all landowners and it cannot be imposed selectively. The county has limited authority to fine people who have weeds. Everyone benefits when we control and prevent the spread of noxious weeds.

The State Noxious Weed Board, a group of citizen volunteers representing all parts of the state, annually adopts and publishes a list of weeds to be controlled or eradicated based on public comment and input from county weed boards. The King County Weed Board customizes the state list and puts out a list of King County's priority weeds that are required by law to be controlled by the property owner. The King County Noxious Weed Control Program, which can be reached at 206-296-0290, has staff with scientific knowledge of weeds and can provide color photos and descriptions of noxious weeds to help citizens identify and eliminate noxious weed infestations.

King County agencies/departments (such as Parks, Roads, WLRD Drainage Services, Transit, etc) are notified of and are required to control noxious weed infestations, much the same way private landowners are notified. The perception that King County is not controlling weeds on County property is a frequently heard and inaccurate one. Our records indicate that there are as many noxious weeds on private property as there are on County lands. The public is much more likely to see weeds on public lands, and it is easier to notice where the weeds are, rather than where they are not or where they have been controlled. County Roads for example, received over 250 notices from the Weed Program last year. The Roads department has tried to be very responsive and have controlled a significant number of weed infestations throughout the County. Increased program funding from the 2002 weed assessment will improve our ability to track and address the issue of weeds on County property.

Giant hogweed - predominantly an urban weed and an escaped garden ornamental, its sap can cause skin blistering and scarring.

Tansy ragwort - likely to infest pastures and roadsides, it has toxins that can be fatal to cows and horses and can be found in milk and honey.

Spotted and diffuse knapweeds - threaten wildlife habitat, pastures, and grasslands by displacing beneficial species.

Purple loosestrife - grows in wetlands and along lakes, rivers and streams; it chokes out wildlife habitat and clogs drainage ditches and irrigation canals. Loosestrife now invades wetlands in 48 states at an estimated cost of $45 million a year for control and loss of forage crops, crowding out 44 native plants and endangering the wildlife that depend on the native plants.

Hydrilla - the most problematic aquatic plant in the U.S., it forms extensive surface mats that destroy freshwater fish habitat and recreation areas.

Parrotfeather - chokes out prime salmon habitat and reduces availability of refuge, exposing salmon to predators.