Weed and Pest Management

IPM is a multifaceted and adaptive approach to controlling pests such as insects, rodents, weeds, and plant diseases.  IPM takes into consideration a variety of factors including costs, benefits, and efficiency of control methods, as well as concern for public health and the environment.

• To effectively reduce populations of invasive, noxious weeds within and adjacent to City of Kirkland owned or managed properties.
•  To create safe sightlines along transportation corridors.
• To protect City infrastructure (e.g., sidewalks and streets).
• To eliminate safety hazards in public walking, bicycling or play areas.
• To restore, create, and protect environmentally valuable areas.

• Physical – Removal of weeds by hand and with hand tools, before they go to seed. 
• Cultural –  Work with the landscape to prevent weeds; shade out weeds with trees, select low maintenance plants to reduce chemical use, use natural wood mulch to prevent weed germination. 
• Mechanical – Use mowers and weed whackers when human power’s not enough.
• Educational - Educate residents about beneficial plants and insects and methods to control invasive species.
• Chemical - When chemicals are used, trained and licensed staff work to minimize the amount of chemicals used to minimize environmental impact.

• Low-mobility, short-lived chemicals are used whenever possible. 
• Only when environmental conditions are right (not raining, not windy).
• Spot application of pesticides rather than broadcast spraying.

For certain types of weeds and site conditions, chemical application is the best control option. It may cause the least amount of environmental impact and have the greatest likelihood of stopping the spread and growth of a noxious weed. Chemical application is mostly used along fence-lines, sidewalk cracks, trails, and other hard to maintain areas. It is the City's policy to apply chemicals sparingly in parks, natural areas, and other open spaces. 

The City of Kirkland works with King County Noxious Weeds to manage regulated weeds using prescribed best practices. Sometimes this requires pesticide application. The City is required by law to manage and remove certain regulated weed species. A few examples found in Kirkland include parrot-feather, meadow knapweed, policeman’s helmet, and giant hogweed.

City of Kirkland Parks and Public Works staff follow Pesticide Application Guidelines(PDF, 328KB)  when applying pesticides on all lands the City owns or manages.

• Parks – open space, developed, and natural areas
• Right of ways, streets, sidewalks, and medians
• Constructed stormwater treatment ponds
• Cross Kirkland Corridor