Stevens County WA Noxious Weed List page

Stevens County 2017 Noxious Weed List
  Adopted on February 18, 2016 pursuant to RCW 17.10.090-17.10.100

INTRODUCTION: The Stevens County Noxious Weed Control Board believes that the prevention and eradication of newly invading noxious weed species yields the greatest return for the resource investment. This is best achieved through an intensive survey and inventory program allowing for early detection and early action. Education and awareness are an integral part of prevention and early detection. Being familiar with what is growing around us is the best way to assure that when a new invader arrives, it will be noticed and dealt with at the most effective stage.

During a public hearing held on February 18, 2016, the Stevens County Noxious Weed Control Board of Directors voted to adopt all Class A, all Class B Designate and certain Class B and C noxious weeds from the 2016 WA State Noxious Weed List.  Even though we include all A and B-designate weeds on our County list, only those that are CURRENTLY FOUND GROWING OR ARE KNOWN TO HAVE GROWN PREVIOUSLY (reported sightings within the past five years) in Stevens Co. are listed here. They are divided according to control requirements: 

Section 1)
These CLASS A weeds have been found as single plants or in very limited populations. Prevention, early detection and eradication is high priority. Cost share may be available at Board discretion.

bighead knapweed
Centaurea macrocephala

clary sage
Salvia sclarea

flowering rush
Butomus umbellatus

meadow clary
Salvia pratensis

Mediterranean sage
Salvia aethiopis

Section 2)

These Class B Designate weeds are located in portions of the county in very limited or moderate populations. Control is required.  Preventing seed production, preventing further spread, reducing existing population sizes, inventory and education are the priorities. Cost share may be available at Board discretion.

annual bugloss Anchusa arvensis

(vipers bugloss)
Echium vulgare

common bugloss Anchusa officinalis

garden loosestrife Lysimachia vulgaris

Kochia scoparia

leafy spurge
Euphorbia esula
cost share

musk thistle
Carduus nutans

perennial pepperweed
Lepidium latifolium
cost share

Tribulus terrestris
cost share

purple loosestrife
Lythrum salicarian

Tamarix ramosissima

Scotch broom
Cytisus scoparius
cost share

Scotch thistle
Onopordum acanthium
cost share

tansy ragwort
Senecio jacobaea
cost share

Abutilon theophrast

wild chervil
Anthriscus sylvestris

yellow archangel
Lamiastrum galeobdolo

Section 3)
The following are Class B Select or Class C Select weeds, elevated by the county weed board to required control everywhere in the county.

black henbane
Hyocyamus niger

Solanum rostratum

hoary alyssum
Berteroa incana

longspine sandbur
Cenchrus longispinus
cost share

Section 4)
These Class B Select weeds are normally grown as ornamentals.  If they are found to have escaped intentional landscape plantings and appear to be spreading off site control may be required

butterfly bush
Buddleja davidii

myrtle spurge
Euphorbia myrsinites

Section 5)

NOTE: Special Control Requirements for the below listed weeds differ dependent upon location in the county. Read Carefully. These weeds are on the State list as Class B Designate in some areas of the county.  This is due to the heavy infestations that occur in portions of the county while only light or moderate infestations occur elsewhere. Outside of the State Designated areas, we’ve made these weeds Class B Select with control requirements differing by weed as follows:


plumeless thistle     Carduus acanthoides- Class B Designate in all areas lying
south of State Highway 20; Class B Select north of State Highway 20. Control, as outlined in section (2) above, is required everywhere in the county.


rush skeletonweed    Chondrilla juncea- Class B Designate, with the same requirements outlined in section (2) above, in all areas north of Township 29 N.  South of here, a control strip at least 40’ wide must be maintained along property boundaries, including travel corridors


yellow starthistle        Centaurea solstitialis  cost share
- Class B Designate, with the same requirements outlined in section (2) above, in all areas except T36 R38 North of Hwy 395/Hwy 20 and West of Pingston Creek Road.  Within this area, a control strip at least 40’ wide must be maintained along property boundaries, including travel corridors

Section 6)
These Class B Select weeds exist in moderate to heavy populations in much of the county. To help prevent further spread of these weeds, a control strip at least 40’ wide must be maintained along property boundaries, including travel corridors. Beyond this strip, the focus will be on assisting landowners one-on-one with control recommendations and technical assistance when requested and utilizing biological control techniques when available. Understand, these weeds are recognized as being extremely detrimental, but due to the widespread infestations, we feel voluntary management is generally the wisest utilization of the Weed Board’s and landowner’s limited resources.

diffuse knapweed
Centaurea diffusa

spotted knapweed
Centaurea biebersteinii

Section 7)
Additionally, at the discretion of the Weed Board, any site infested with state listed noxious weeds, whether within an area where the weeds are normally required to be controlled or not, that poses a threat of the spread of propagules (seeds, roots, vegetative parts) through the transport of contaminated materials, may require control and may be subject to enforcement by the Board.  These sites include but are not limited to gravel pits, quarries, landscape materials, etc.

Click here for an easily printable PDF version of the Stevens Co 2016 Weed List 

You can view and print a brochure of all weeds on the State Noxious Weed list by accessing the
State Weed List 2017 (PDF) here.  WAC 16-750, with official definitions, weed list regions and weed class designations can be accessed here.

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of some of the legal terms mentioned above can be found in our glossary


EACH COUNTY WEED BOARD MUST adopt all State classified A and B-designate weeds on their County Weed Lists. However, counties may choose which of the State classified B and C weeds will be placed on their County Weed List dependent upon the individual concerns of each county. Additionally, a County Weed Board may elevate the classification and corresponding control requirements of any weed on the State Weed List.

NOT INCLUDING A NOXIOUS WEED ON our County Weed List does not mean that it has no significant impact or that it is not found in the county. In order to use resources (time, equipment, dollars) in the most effective and efficient manner possible, the SCNWCB has chosen to limit the number of State classified B and C weeds on our county list. Unfortunately, several of the noxious weeds on the State Weed list are already established well beyond the point where we feel a significant impact can be made towards reducing the population of the weed without a substantial allocation of resources going toward that one weed.

IN THE CASE OF WEEDS that are well established, wide spread and/or not included on our list, we feel a strong education/awareness program with an emphasis on voluntary landowner compliance is the best use of resources. Biological control agents (usually insects) can be one of the best management tools for weeds in this category.  Many bioagents are already established in the county and the impact they are having on weeds such as diffuse and spotted knapweed, Canada, plumeless and musk thistle, rush skeletonweed and St. Johnswort is visible.  The redistribution of bioagents within the county and the continued build up of successful agents or introduction of new agents, when available, will be encouraged and supported by the weed board.  Support by the weed board may include using staff or volunteer labor, purchasing or otherwise making available appropriate equipment, sponsoring training opportunities and buying the biocontrols or sharing the cost with landowners as approved by the Board.

For a full explanation of how YOU can participate in the State's Weed Listing Process, please refer to this document.

New procedure for making changes to our County weed list beginning in 2015.  View the explanation of the new process here.

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