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Weed Board
222 North Havana, Room 112
Spokane, WA 99202
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Weed Board Frequently Asked Questions

I have some weeds growing on my property and I am not sure if they are noxious or not, can someone come look at them and tell me what they are and how to get rid of them?

One of our inspectors can meet with you on your property and help you identify the weeds and offer control recommendations. To request an inspection of your property, just call our office at (509) 477-5777 for the form, download the form from this website, or submit an Investigation Request from this website.

What do I do if my neighbor has weeds and isn't doing anything about them?

Call our office and we will send you an Investigation Request Form to fill out with the location of the weeds; return it to our office, or download the form online and mail or fax it to our office. Or you can choose to submit an Investigation Request from this website .

Why do I have a weed charge on my tax statement?

It is the source of funding for the Spokane County Noxious Weed Control Board, it allows us to carry out the mandates of RCW 17.10 and WAC 16-750.

Is the Noxious Weed Board the agency that controls weeds on the County's right-of-way?

No. The County Engineer's Road Department is responsible for controlling weeds that grow along the County's road right-of-ways. Contact the County Engineers at (509) 477-3600 for questions or concerns regarding weeds on the right-of-ways or on County owned property.

What should I spray my weeds with?

It will depend on what noxious weeds you have, their stage of growth and other site-specific variables. Please contact our office for more information on herbicides, or refer to the information provided on this website under Noxious Weed Control Recommendations. Remember to always follow the label directions when applying herbicides.

Why are noxious weeds considered a material defect to my property?

Because just like a leaky roof or poor foundation, noxious weeds are a detriment to the value of the property and will take time and money to get under control.

How do I get a Pesticide License?

Contact the local WA Department of Agriculture at (509) 533-2690.

Do grazing animals and wildlife eat noxious weeds?

This depends on the animal and the type of weed. Rarely do animals prefer to eat noxious weeds. Most often on pastures infested with weeds, the animals will graze the desirable vegetation, causing an increase in the problem weeds.

Elk prefer native forbs and grasses and will starve to death on ranges infested with Spotted knapweed and Leafy spurge. Doves readily eat and distribute Leafy spurge seeds. Leafy spurge can be grazed by sheep, but is toxic to cattle and horses can eat Musk thistle blooms, while Russian knapweed is toxic to them.

Will mowing alone control my noxious weeds?

Generally you will find that this form of control will not work all summer because the plants will start to bloom lower than your mower blade. Mowing is one important method in stopping seed production, but should be used along with other control measures to stop the spread of noxious weeds. For example, mowing is not entirely effective on Spotted knapweed or Leafy spurge, but a diligent 3 year mowing program on Canada thistle may achieve around 90% control if mowed at the early bud stage of growth (several times during the growing season) followed by a fall application of herbicides. This will increase the control efforts and help to cause the thistle to collapse.

I'm not going to worry about my weeds and let nature takes it course and leave my land "natural".

This is an open invitation for noxious weeds to come into an area. If land is not managed correctly, then the most aggressive, non-native plants that are established nearby may take over an area, choking out native grasses and forbs. The knapweed infestation in Montana is contributing to the death of over 200 elk per year and several cattle ranches have been abandoned due to the overwhelming invasion of Leafy spurge and knapweed.

It is important to keep in mind that biological control is a slow process and will not eradicate noxious weeds. However, they do have their place in an integrated pest management plan. When used in conjunction with mechanical, cultural and/or chemical control methods, bio’s can improve the overall control efforts. The use of bio’s alone does not comply with the Spokane County Noxious Weed Control Board’s Policy or the WA State Noxious Weed Law.

I don't want to spray my weeds because herbicides are very toxic and will remain in the soil where they are sprayed.

Most herbicides are considered low or moderately toxic. All chemicals have a half-life in the environment. Half-life is defined as the amount of time it takes to biodegrade one half of the original amount. Herbicides are broken down by sunlight and microbial activity in the soil.

All chemicals are assigned Lethal Dose (LD 50) numerical values through certain testing procedures. What LD 50 means is the dose or amount of a pesticide which can kill 50% of the test animals when eaten or absorbed through the skin. LD50 is expressed in milligrams of chemical per kilogram of body weight of the test animal (mg/kg). The lower the LD50 the more acutely toxic the chemical.

Chemical Name LD50 Half Life
Gasoline 19 - - -
Caffeine 190 - - -
2,4-D 300 to 1,000 7 to 28 days
Aspirin 1240 - - -
Banvel 1700 5 months
Table Salt 3320 - - -
Telar/Glean 5545 3 months
Roundup 5600 7.5 days
Tordon 8200 5 months/pint