[Filed December 1, 2025, 2:17 p.m., effective January 1, 2026]

Effective Date of Rule: January 1, 2026.

Purpose: The Washington state noxious weed list provides the basis for noxious weed control efforts for county and district weed control boards, as well as other entities. This rule-making order amends chapter 16-750 WAC noxious weed list.

WAC 16-750-005 Class A noxious weed additions:

WAC 16-750-015 Class C noxious weed additions:

Citation of Rules Affected by this Order: Amending WAC 16-750-005 and 16-750-015.


•	Waterhemp (Amaranthus tuberculatus)
•	Delta arrowhead (Sagittaria platyphylla)


•	Black locust (Robinia pseudoacacia)
•	Norway maple (Acer platanoides)

Statutory Authority for Adoption: Chapter 17.10 RCW.

Other Authority: Chapter 34.05 RCW.

Adopted under notice filed as WSR 25-20-021 on September 22, 2025.

Changes Other than Editing from Proposed to Adopted Version: A technical error was corrected for the Norway maple proposal. The statement regarding sterile cultivars was removed.

Number of Sections Adopted in Order to Comply with Federal Statute: New 0, Amended 0, Repealed 0; Federal Rules or Standards: New 0, Amended 0, Repealed 0; or Recently Enacted State Statutes: New 0, Amended 0, Repealed 0.

Number of Sections Adopted at the Request of a Nongovernmental Entity: New 0, Amended 0, Repealed 0.

Number of Sections Adopted on the Agency's own Initiative: New 0, Amended 2, Repealed 0.

Number of Sections Adopted in Order to Clarify, Streamline, or Reform Agency Procedures: New 0, Amended 0, Repealed 0.

Number of Sections Adopted using Negotiated Rule Making: New 0, Amended 0, Repealed 0; Pilot Rule Making: New 0, Amended 0, Repealed 0; or Other Alternative Rule Making: New 0, Amended 0, Repealed 0.

Date Adopted: November 5, 2025.

AMENDATORY SECTION(Amending WSR 24-23-085, filed 11/19/24, effective 1/1/25)

WAC 16-750-005State noxious weed list—Class A noxious weeds.

Common Name	Scientific Name
broom, French	Genista monspessulana
broom, Spanish	Spartium junceum
common crupina	Crupina vulgaris
cordgrass, common	Spartina anglica
cordgrass, dense-flowered	Spartina densiflora
cordgrass, salt meadow	Spartina patens
cordgrass, smooth	Spartina alterniflora
delta arrowhead	Sagittaria platyphylla
dyer's woad	Isatis tinctoria
eggleaf spurge	Euphorbia oblongata
false brome	Brachypodium sylvaticum
floating primrose-willow	Ludwigia peploides
flowering rush	Butomus umbellatus
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
meadow clary	Salvia pratensis
oriental clematis	Clematis orientalis
Palmer amaranth	Amaranthus 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
Syrian bean-caper	Zygophyllum fabago
Texas blueweed	Helianthus ciliaris
thistle, Italian	Carduus pycnocephalus
thistle, marsh	Cirsium palustre
thistle, milk	Silybum marianum
thistle, slenderflower	Carduus tenuiflorus
thistle, Turkish	Carduus cinereus
variable-leaf milfoil and hybrids	Myriophyllum heterophyllum Myriophyllum heterophyllum x Myriophyllum hippuroides
waterhemp	Amaranthus tuberculatus
wild four o'clock	Mirabilis nyctaginea

AMENDATORY SECTION(Amending WSR 25-08-024, filed 3/25/25, effective 4/25/25)

WAC 16-750-015State noxious weed list—Class C noxious weeds.

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
blackberry, evergreen	Rubus laciniatus
blackberry, Himalayan	Rubus bifrons
blackgrass	Alopecurus myosuroides
black locust	Robinia pseudoacacia
buffalobur	Solanum rostratum
cereal rye	Secale cereale
common barberry	Berberis vulgaris
common catsear	Hypochaeris radicata
common groundsel	Senecio vulgaris
common holly	Ilex aquifolium, except where commercially grown
common St. Johnswort	Hypericum perforatum
common teasel	Dipsacus fullonum
curly-leaf pondweed	Potamogeton crispus
English hawthorn	Crataegus monogyna
English ivy 4 cultivars only:	Hedera hibernica 'Hibernica'
	Hedera helix 'Baltica'
	Hedera helix 'Pittsburgh'
	Hedera helix 'Star'
Eurasian watermilfoil hybrid	Myriophyllum spicatum x M. sibiricum
field bindweed	Convolvulus arvensis
fragrant water lily	Nymphaea odorata
green alkanet	Pentaglottis sempervirens
hairy whitetop	Lepidium appelianum
hoary cress	Lepidium draba
Italian arum	Arum italicum
Japanese eelgrass	Nanozostera japonica
jointed goatgrass	Aegilops cylindrica
jubata grass	Cortaderia jubata
lawnweed	Soliva sessilis
longspine sandbur	Cenchrus longispinus
Medusahead	Taeniatherum caput-medusae
nonnative cattail species and hybrids	Including, but not limited to, Typha angustifolia, T. domingensis and T. x glauca
Norway maple	Acer platanoides
old man's beard	Clematis vitalba
oxeye daisy	Leucanthemum vulgare
pampas grass	Cortaderia selloana
perennial sowthistle	Sonchus arvensis ssp. 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
thistle, bull	Cirsium vulgare
thistle, Canada	Cirsium arvense
tree-of-heaven	Ailanthus altissima
ventenata	Ventenata dubia
white cockle	Silene latifolia
wild carrot (except subs. sativus where grown commercially or for food)	Daucus carota
yellow flag iris	Iris pseudacorus
yellow toadflax	Linaria vulgaris