Vegetation Management

The City of Covington continuously monitors and maintains roadside vegetation within the city limits.  The City controls roadside vegetation primarily by mowing and pruning. The spraying of herbicides is used to supplement mowing operations.

Why do we manage roadside vegetation?
Weeds and grasses along roadsides create a fire hazard in summer and fall, can obstruct drainage ditches, potentially limit driver visibility, and can directly lead to the deterioration of roads if left uncontrolled. Also, cities are mandated by the state to control certain noxious weeds on its properties.

City maintenance crews provide vegetation management along our streets as does the City’s landscape contractor. The landscape contractor maintains vegetation by both mechanical methods as well as through the use of herbicides. They will also use approved growth inhibitors on certain shrubs to help control their growth within the right-of-way.

Another reason the City provides roadside maintenance is to control the spread of noxious weeds. The City is required by state law to eradicate Class A weeds as well as contain other weeds as needed. To view the noxious list and their applicable laws visit: https://www.kingcounty.gov/services/environment/animals-and-plants/noxious-weeds/laws.aspx

How do we manage roadside vegetation?

Roadside vegetation is managed through a combination of mowing, pruning, and the application of herbicides. The City generally maintains the roadway shoulders where grasses, invasive species and woody plants can be found. Areas which are free of such vegetation typically do not require treatment.

Mowing roadside vegetation is very labor intensive. The City does not have the resources to mow all areas within the City that have roadside vegetation. Areas may need to mowed multiple times per year to be adequately controlled.

What herbicides do we use and when do we apply them?

The City typically uses the following herbicide products for vegetation management:

  • Roundup or Crossbow

Herbicides are applied during dry weather periods and in conjunction with all laws. Information on products used by the City can be found on the manufacturer’s website. All applications are documented as required by the Washington State Department of Agriculture.

How are herbicides selected and how do they work?

The City of Covington consults annually with professionals in the field to determine appropriate herbicide products. All products selected for use are approved by the Environmental Protection Agency.

How are herbicides applied and what training do City employees receive?

City of Covington employees overseeing herbicide applications in the field must possess a Washington State herbicide applicator’s license. Herbicides are mixed with water and applied with a specialized truck which is designed to apply herbicides precisely at programmed application rates. The City applies herbicides to right-of ways by hand.