March 7, 2012
King County launches annual roadside weed control program
The King County Road Services Division will begin its roadside weed control program in unincorporated areas of the county beginning April 9, 2012. As part of the program, certified technicians will perform controlled herbicide spraying along some road shoulders through the summer to reduce safety hazards for pedestrians, motorists and bicyclists. The spraying will also control noxious weeds that are toxic to some animals and pose environmental risks to native vegetation.
As in past years, residents who do not want crews to spray county right-of-way that abuts their property may post “owner will maintain” signs. Those residents, however, must sign an agreement with the County to maintain the right-of-way themselves. Maintenance agreements must be completed and returned to the Roads Services Division before the “owner will maintain” signs can be issued. Maintenance agreements should be received by the Road Services Division by April 4, 2012.
The signs are once again being provided to property owners at no charge. The County will notify property owners who asked to maintain right-of-way last year. Signs and copies of the maintenance agreement are available by calling (206) 296-8100 or toll-free 1-800-KC ROADS. The maintenance agreement is also available on the Road Services Division’s roadside weed control website at:
The Road Services Division uses small amounts of herbicides on a carefully controlled basis. Trained technicians use only those herbicides approved by the United States Environmental Protection Agency, Food and Drug Administration and the state Department of Agriculture. Applications are additionally guided by best management practices that include follow-up monitoring and soil testing.
No spraying is conducted near water including rivers, streams, wetlands, bridge abutments, guardrails near water, ditches, levees, back slopes, or in moratorium zones, which include the Snoqualmie Valley and Vashon and Maury islands. Spraying in moratorium zones is only conducted in very limited situations mandated by state or local law and/or by action of the King County Weed Board.
Herbicide applications are designed to keep road shoulders safe for bicyclists and pedestrians, prevent root systems from damaging roadways and reduce sod buildup that causes road flooding and icy conditions in winter. Weed control also reduces fires that can ignite uncontrolled vegetation and overgrowth that can causes accidents due to reduced visibility.
The Road Services Division will also be removing all tansy ragwort from right-of-way due to the flowering weed’s danger to animals. State and local laws require the removal of tansy ragwort and other noxious weeds. Residents who maintain right-of-way are asked to place vegetation that may contain tansy ragwort in sealable bags to prevent the spread of the weed.