Noxious Weeds

A woman in a high viz shirt stuffing pulled poison hemlock plants into the bed of a truck.

Our Program

Skagit County’s Noxious Weed program tracks and treats noxious weeds (invasive plants that the County has determined need to be controlled). Noxious weeds threaten important habitat and valuable resources like clean water and useable land. Some noxious weeds are also poisonous to people and livestock.

Our program treats weeds on public lands and offers advice to people treating noxious weeds on their own property. It’s every landowner’s job to control and prevent the spread of noxious weeds within and from their property.

Noxious Weed Lists

Noxious weeds are divided into three classifications: Class A weeds, Class B weeds, and Class C weeds. Click on the drop down menus below to view weed lists for each class.

To find pictures of and more information on these weeds, visit the Washington State Noxious Weed Control Board website.

Class A Weeds

Class A weeds are non-native species whose distribution in Washington is still limited. Preventing new infestations and eradicating existing infestations are the highest priority.

Eradication of all Class A plants on public and private land is required by law.

Class A Weeds (required for control)
Common Name	Scientific Name
common crupina	Crupina vulgaris
cordgrass, common	Spartina anglica
cordgrass, dense-flowered	Spartina densiflora
cordgrass, saltmeadow	Spartina patens
cordgrass, smooth	Spartina alterniflora
dyer’s woad	Isatis tinctoria
eggleaf spurge	Euphorbia oblongata
false brome	Brachypodium sylvaticum
floating primrose-willow	Ludwigia peploides
flowering rush	Butomus umbellatus
French broom	Genista monspessulana
garlic mustard	Alliaria petiolata
giant hogweed	Heracleum mantegazzianum
goatsrue	Galega officinalis
hydrilla	Hydrilla verticillata
Johnsongrass	Sorghum halepense
knapweed, bighead	Centaurea macrocephala
knapweed, Vochin	Centaurea nigrescens
kudzu	Pueraria montana var. lobata
marsh thistle	Cirsium palustre
meadow clary	Salvia pratensis
oriental clematis	Clematis orientalis
palmer amaranth	ameranthus palmeri
purple starthistle	Centaurea calcitrapa
reed sweetgrass	Glyceria maxima
ricefield bulrush	Schoenoplectus mucronatus
round leaf bittersweet	Celastrus orbiculatus
sage, clary	Salvia sclarea
sage, Mediterranean	Salvia aethiopis
silverleaf nightshade	Solanum elaeagnifolium
small-flowered jewelweed	Impatiens parviflora
South American spongeplant	Limnobium laevigatum
Spanish broom	Spartium junceum
Syrian beancaper	Zygophyllum fabago
Texas blueweed	Helianthus ciliaris
thistle, Italian	Carduus pycnocephalus
thistle, milk	Silybum marianum
thistle, slenderflower	Carduus tenuiflorus
thistle, Turkish	Carduus cinereus
variable-leaf milfoil and hybrids	Myriophyllum heterophyllum
wild four-o'clock	Mirabilis nyctaginea

Class B Weeds

Class B weeds are non-native species whose distribution is limited to portions of Washington State.

Species are designated for control in state regions where they are not yet widespread. Prevention of new infestations in these areas is the primary goal.
In regions where a Class B species is already abundant, control is decided at the local level. Containment of these weeds is the primary goal so that they do not spread into un-infested regions.
The Washington State Noxious Weed Board or a County Noxious Weed Board can designate a Class B noxious weed for mandatory control.

Class B Designate Weeds (required for control)
Common Name	Scientific Name
blueweed	Echium vulgare
Brazilian elodea	Egeria densa
bugloss, annual	Lycopsis arvensis
bugloss, common	Anchusa officinalis
camelthorn	Alhagi maurorum
common reed (nonnative genotypes only)	Phragmites australis
Dalmatian toadflax	Linaria dalmatica ssp. dalmatica
European coltsfoot	Tussilago farfara
fanwort	Cabomba caroliniana
gorse	Ulex europaeus
grass-leaved arrowhead	Sagittaria graminea
hairy willowherb	Epilobium hirsutum
hanging sedge	Carex pendula, Carex pendula subsp. pendula and Carex pendula subsp. agastachys
hawkweed oxtongue	Picris hieracioides
hawkweed, orange	Hieracium aurantiacum
hawkweeds: All nonnative species & hybrids of the meadow subgenus	Hieracium, subgenus Pilosella
hoary alyssum	Berteroa incana
houndstongue	Cynoglossum officinale
indigobush	Amorpha fruticosa
knapweed, black	Centaurea nigra
knapweed, brown	Centaurea jacea
knapweed, diffuse	Centaurea diffusa
knapweed, meadow	Centaurea × gerstlaueri
knapweed, Russian	Rhaponticum repens
knapweed, spotted	Centaurea stoebe
knotweed, giant	Fallopia sachalinensis
knotweed, Himalayan	Persicaria wallichii
kochia	Bassia scoparia
loosestrife, garden	Lysimachia vulgaris
Malta starthistle	Centaurea melitensis
parrotfeather	Myriophyllum aquaticum
perennial pepperweed	Lepidium latifolium
policeman’s helmet	Impatiens glandulifera
puncturevine	Tribulus terrestris
rough chervil	Chaerophyllum temulum
rush skeletonweed	Chondrilla juncea
saltcedar	Tamarix ramosissima
shiny geranium	Geranium lucidum
spurge laurel	Daphne laureola
spurge, leafy	Euphorbia virgata
spurge, myrtle	Euphorbia myrsinites
sulfur cinquefoil	Potentilla recta
thistle, musk	Carduus nutans
thistle, plumeless	Carduus acanthoides
thistle, Scotch	Onopordum acanthium
velvetleaf	Abutilon theophrasti
water primrose	Ludwigia hexapetala
white bryony	Bryonia alba
wild basil	Clinopodium vulgare
wild chervil	Anthriscus sylvestris
yellow archangel	Lamiastrum galeobdolon
yellow floating heart	Nymphoides peltata
yellow starthistle	Centaurea solstitialis

**Class B Non-Designate Weeds (required for control)**
Common Name	Scientific Name
knotweed, Bohemian	Fallopia × bohemica
knotweed, Japanese	Fallopia japonica
poison hemlock	Conium maculatum
Scotch broom	Cytisus scoparius
tansy ragwort	Jacobaea vulgaris

**Class B Non-Designate Weeds (optional control)**
Common Name	Scientific Name
common fennel, (except bulbing fennel)	Foeniculum vulgare except F. vulgare var. azoricum)
common tansy	Tanacetum vulgare
Eurasian watermilfoil	Myriophyllum spicatum
hawkweeds: All nonnative species & hybrids of the wall subgenus	Hieracium, subgenus Hieracium
herb-Robert	Geranium robertianum
lesser celandine	Ficaria verna
loosestrife, purple	Lythrum salicaria
loosestrife, wand	Lythrum virgatum
Ravenna grass	Tripidium ravennae
spurge flax	Thymelaea passerina
butterfly bush	Buddleja davidii
yellow nutsedge	Cyperus esculentus

Class C Weeds

Class C weeds are non-native species that are either already widespread in Washington or are of special interest to the agricultural industry.

The Class C status allows a county to enforce control if it is beneficial to that county (for example: to protect crops).

Counties that do not choose to enforce control of these weeds may choose to provide education or technical support for the removal or control of these weeds.

**Class C Weeds (required for control)**
Common Name	Scientific Name
common teasel	Dipsacus fullonum
Italian arum	Arum italicum
thistle, bull	Cirsium vulgare
thistle, Canada	Cirsium arvense

**Class C Weeds (optional control)**
Common Name	Scientific Name
absinth wormwood	Artemisia absinthium
Austrian fieldcress	Rorippa austriaca
babysbreath	Gypsophila paniculata
Beach grass, European, American, and hybrids	Ammophila arenaria, A. breviligulata, and A. arenaria x breviligulata
black henbane	Hyoscyamus niger
blackgrass	Alopecurus myosuroides
buffalobur	Solanum rostratum
cereal rye	Secale cereale
common barberry	Berberis vulgaris
common catsear	Hypochaeris radicata
common groundsel	Senecio vulgaris
common St. Johnswort	Hypericum perforatum
curlyleaf pondweed	Potamogeton crispus
English hawthorn	Crataegus monogyna
English ivy - four cultivars only	Hedera helix ‘Baltica’, ‘Pittsburgh’, and ‘Star’, and H. hibernica ‘Hibernica’
Eurasian watermilfoil hybrid	Myriophyllum spicatum x Myriophyllum sibiricum
evergreen blackberry	Rubus laciniatus
field bindweed	Convolvulus arvensis
fragrant waterlily	Nymphaea odorata
green alkanet	Pentaglottis sempervirens
hairy whitetop	Lepidium appelianum
Himalayan blackberry	Rubus bifrons (Rubus armeniacus)
hoary cress	Lepidium draba
Japanese eelgrass	Nanozostera japonica
jubata grass	Cortaderia jubata
jointed goatgrass	Aegilops cylindrica
lawnweed	Soliva sessilis
longspine sandbur	Cenchrus longispinus
medusahead	Taeniatherum caput-medusae
nonnative cattail species & hybrids (reminder, does not include the native common cattail, Typha latifolia)	Typha species
old man's beard	Clematis vitalba
oxeye daisy	Leucanthemum vulgare
Pampas grass	Cortaderia selloana
perennial sowthistle	Sonchus arvensis
reed canarygrass	Phalaris arundinacea
Russian olive	Elaeagnus angustifolia
scentless mayweed	Tripleurospermum inodorum
smoothseed alfalfa dodder	Cuscuta approximata
spikeweed	Centromadia pungens
spiny cocklebur	Xanthium spinosum
spotted jewelweed	Impatiens capensis
Swainsonpea	Sphaerophysa salsula
tree-of-heaven	Ailanthus altissima
ventenata	Ventenata dubia
white cockle	Silene latifolia
wild carrot (except where commercially grown)	Daucus carota
yellow flag iris	Iris pseudacorus
yellow toadflax	Linaria vulgaris

Current Grant Projects

The Skagit County Noxious Weed Control Board has two grant based programs that are both funded through Washington State Department of Agriculture: The Spartina Control Program and the Knotweed Control Program.

Spikey spartina (cord grass) in a salt marsh.

Spartina Control

Himalayan knotweed with large green leaves and bunches of tiny cream-colored flowers.

Knotweed Control

Your Part

You can protect Skagit County from noxious weeds, too!

You can help prevent the spread of noxious weeds by:

Obeying noxious weed laws (RCW 17.10).
Identifying plants before buying, gifting, or planting them.
Never dumping pond or aquarium water into a lake or stream.
Always checking your boat trailer for weeds before and after launching.
Always checking your vehicle, camping equipment, clothing, etc. for weeds and seeds before departing.
Disposing of noxious weeds properly.
Reporting noxious weeds.
Covering compost and mulch piles.

Spurge laurel with long, glossy, dark green leaves and small bright green flowers.

Green, arrow-shaped Italian arum leaves with light yellow veins.

You can control infestations on your property by:

Properly removing and destroying active infestations.
Preventing seed production.
Using herbicides properly according to their labels.
Re-planting with appropriate species to prevent re-growth of noxious weeds.

Different weeds need different control methods. Visit the Washington State Noxious Weed Control Board website or contact us for more information on treating specific weeds.

Noxious Weed Control Board Districts

Skagit County is divided into five Noxious Weed Control Districts, each with a representative on the Skagit County Noxious Weed Control Board to provide input and guide program activities.

Learn more about the Noxious Weed Control Board's meetings, current members, and vacancies on our Boards and Committees page.

Noxious Weed Control Board Application

Skagit County Noxious Weed Control Board Districts

District 1

Beginning at the intersection of the North line of the Skagit County boundary and the centerline of State Route 9;Said intersection also being on the North line of Section 6, Township 36 North, Range 5 East, W.M.; Thence Southerly along the centerline of said State Route 9 to its intersection with the centerline of State Route 20;Thence Westerly along the centerline of said State Route 20 to its intersection with the medial line of the nautical fairway of Swinomish Channel; Said nautical fairway being delineated on NOAA Nautical Chart Number 18427, Anacortes to Skagit Bay, 24th Ed., May 2013;Thence Southerly and Southwesterly along said medial line and the Southwesterly extension thereof, to its intersection with the Southwestern boundary of Skagit County; Thence Northwesterly, Northerly and Easterly along the Skagit County boundary to the point of beginning.

District 2

Beginning at the intersection of the centerline of State Route 9 with the centerline of State Route 20;Said intersection being located in the Southwest ¼ of Section 24, Township 35 North, Range 4 East, W.M.; Thence Westerly along the centerline of said State Route 20 to its intersection with the medial line of the nautical fairway of Swinomish Channel; Said nautical fairway being delineated on NOAA Nautical Chart Number 18427, Anacortes to Skagit Bay, 24th Ed., May 2013;Thence Southerly and Southwesterly along said medial line and the Southwesterly extension thereof, to its intersection with the Southwestern boundary of Skagit County; Thence Southeasterly and Easterly along the Skagit County boundary to its intersection with the centerline of State Route 9;Said intersection also being on the South line of Section 32, Township 33 North, Range 5 East, W.M.; Thence Northerly along said centerline of State Route 9 to the point of beginning.

District 3

Beginning at the intersection of the Northern boundary of Skagit County and the centerline of State Route 9;Said intersection also being on the North line of Section 6, Township 36 North, Range 5 East, W.M.; Thence Southerly along the centerline of said State Route 9 to its intersection with the centerline of State Route 20;Thence Westerly along the centerline of said State Route 20 to its intersection with the centerline of State Route 9;Said intersection being located in the Southwest ¼ of Section 24, Township 35 North, Range 4 East, W.M.; Thence Southerly along the centerline of State Route 9 to its intersection with the Southern boundary of Skagit County; Said intersection also being on the South line of Section 32, Township 33 North, Range 5 East, W.M.; Thence Easterly along the Southern boundary of Skagit County to its intersection with the East Range line of Range 7 East, W.M.; Said intersection also being the Southeast corner of Section 36, Township 33 North, Range 7 East, W.M.; Thence Northerly along said East Range line to its intersection with the medial line of Finney Creek; Thence Northwesterly along the medial line of Finney Creek to its intersection, if extended, with the medial line of the Skagit River; Thence Southwesterly along the medial line of the Skagit River to the medial line of Grandy Creek, if extended; Thence Northerly along the extension of the medial line of Grandy Creek, and the medial line of Grandy Creek, to its intersection with the centerline of State Route 20;Thence Westerly along the centerline of State Route 20, to its intersection with the centerline of Baker Lake Road; Thence Northwesterly along the centerline of Baker Lake Road, to its intersection with the Northern boundary of Skagit County; Said intersection also being on the North line of Section 02, Township 36 North, Range 8 East, W.M.; Thence Westerly along the Northern boundary of Skagit County to the point of beginning.

District 4

Beginning at the intersection of the Northern boundary of Skagit County and the centerline of Baker Lake Road; Said intersection also being on the North line of Section 02, Township 36 North, Range 8 East, W.M.; Thence Easterly along the Northern boundary of Skagit County to its intersection with the Western boundary of Okanogan County; Thence Southerly along the Eastern boundary of Skagit County to its intersection with the Western boundary of Chelan County; Thence continuing Southwesterly along the Eastern boundary of Skagit County to its intersection with the South Township line of Township 35 North, W.M.; Thence West along the said South Township line to its intersection with the medial line of the North Fork Cascade River; Said intersection also being on the South line of Section 35, Township 35, Range 13 East, W.M.; Thence Northwesterly and Southwesterly along the said medial line of the North Fork Cascade River and its extension, to its intersection with the medial line of the Cascade River; Thence Northwesterly along the said medial line of the Cascade River and its extension, to its intersection with the medial line of the Skagit River; Thence Westerly along the medial line of the Skagit River, to the medial line of Grandy Creek, if extended; Thence Northerly along the extension of the medial line of Grandy Creek, and the medial line of Grandy Creek, to its intersection with the centerline of State Route 20;Thence Westerly along the centerline of State Route 20, to its intersection with the centerline of Baker Lake Road; Thence Northwesterly along the centerline of Baker Lake Road, to the point of beginning.

District 5

Beginning at the Southeast corner of Township 33, Range 7 East, W.M.; Said Southwest corner also being on the Southern boundary of Skagit County; Thence Easterly along the Southern boundary of Skagit County, to its intersection with the Western boundary of Chelan County; Thence Northerly along the Eastern boundary of Skagit County to its intersection with the South Township line of Township 35 North, W.M.; Thence West along the said South Township line to its intersection with the medial line of the North Fork Cascade River; Said intersection also being on the South line of Section 35, Township 35, Range 13 East, W.M.; Thence Northwesterly and Southwesterly along the said medial line of the North Fork Cascade River and its extension, to its intersection with the medial line of the Cascade River; Thence Northwesterly along the said medial line of the Cascade River and its extension, to its intersection with the medial line of the Skagit River; Thence Westerly along the medial line of the Skagit River, to the medial line of Finney Creek, if extended; Thence Southeasterly along the extension of the medial line of Finney Creek, and the medial line of Finney Creek, to its intersection with the East Range line of Range 7 East, W.M.;
Thence Southerly along said East Range line to the point of beginning.

Meeting Minutes and Agendas

2026

1/15 Agenda | Minutes

1/28 Agenda | Minutes

4/16 Agenda | Minutes

7/17 Agenda | Delayed

2025

1/16 Agenda | Minutes

4/17 Agenda | Minutes

7/17 Agenda | Minutes

11/20 Agenda | Minutes

2024

1/18 Agenda | Minutes

4/18 Agenda | Minutes

7/18 Agenda | Minutes

11/21 Agenda | Minutes

Noxious Weed Laws

In recognition of the economic and ecological threats caused by invasive, non-native plant, there are both County and State laws in place to support noxious weed control.

Skagit County Code:

Skagit County Code: Chapter 6.56

State Laws:

Chapter 16-750 WAC - Washington State Noxious Weed List and Schedule of Monetary Penalties
Chapter 17.10 RCW - Noxious Weeds - Control Boards
Chapter 17.04 RCW - Weed Districts
Chapter 17.06 RCW - Intercounty Weed Districts
Chapter 16-752 WAC - Noxious Weed Control (WSDA's Weed Law)
Chapter 16-402 WAC - Freedom from Infestation (WSDA's Weed Law)
Chapter 17.24 RCW - Insect Pests and Plant Diseases (WSDA's Weed Law

Our Program

Class A Weeds (required for control)

Class B Designate Weeds (required for control)

Class B Non-Designate Weeds (required for control)

Class B Non-Designate Weeds (optional control)

Class C Weeds (required for control)

Class C Weeds (optional control)

Current Grant Projects

Your Part

Noxious Weed Control Board Districts

Meeting Minutes and Agendas

Noxious Weed Laws