HomeMy WebLinkAboutM_King County Noxious Weed List_King County_190605_V1KING COUNTY’SNoxious WeedControl Program
Poison-hemlock, Class B noxious weed
Department of
Natural Resources and Parks
Water and Land Resources Division
Noxious Weed Control Program
2019 King CountyNoxious Weed List
STOP THE INVADERS!
Photo credit: Karen Peterson
The Program protects the natural and
economic resources of county residents. We
ensure that noxious weeds that are regulated
in King County are controlled. Our weed
specialists teach property owners to identify
and control noxious weeds so they do not
spread to other properties. We make sure
public agencies control regulated noxious
weeds on roads and public lands to reduce
impacts to public resources and prevent
spread to neighboring lands.
If you are unsure how to identify or control a
regulated noxious weed or have a hardship
that prevents you from doing so, the
program can provide assistance. If a property
owner refuses to control a regulated noxious
weed, state law authorizes the county weed
board to pursue control through a notice of
violation and, if necessary, bill the landowner
for the control cost. We work to avoid this
and we do all we can to help landowners find
a solution that works for them.
DEFINITIONS (RCW 17.10, WAC 16-750)
Noxious Weed - a non-native plant that
when established is highly destructive,
competitive, or difficult to control
Control - in a given year, prevent all seed
production and dispersal of all propagative
parts capable of forming new plants.
Eradicate - completely eliminate a noxious
weed within an area of infestation.
THE NOXIOUS WEED PROGRAM IS HERE TO HELP:
• Technical assistance with ID and control
• Free workshops and info booths at events
• Brochures, fact sheets and weed guides
• Control assistance for high priority weeds
• Disposal vouchers for regulated weeds
• Weed pullers and knotweed injectors for loan
OUR MISSION:
To provide benefits to the environment,
recreation, public health and economic
resources of King County by preventing and
minimizing harmful impacts of noxious weeds.
You can help fight noxious weeds by planting
only non-invasive plants, disposing of noxious
weeds responsibly, reporting infestations of
regulated noxious weeds that are not being
controlled, and controlling weeds on your own
property. Thank you for helping!
CONTACT US:
King County Noxious Weed Control Program
201 S. Jackson St., Suite 600, Seattle WA 98104
206-477-WEED (206-477-9333)
noxious.weeds@kingcounty.gov
Visit our website and report weeds at kingcounty.gov/weeds
This information can be
made available in alternate formats. Call 206-477-9333 or TTY: 711 NOXIOUS WEEDS are a danger to our environment and the economy. These introduced species cost our region millions of dollars in lost agricultural production, environmental degradation and added maintenance costs. Once invasive plants spread to natural areas, they harm native plants and wildlife and can be impossible to eradicate.Forest invaders garlic mustard, English ivy and yellow archangel can damage trees, overwhelm native species and harm wildlife habitat.Invasive plants Scotch broom, knotweed, butterfly bush and Himalayan blackberry impede efforts to restore rivers and reforest timberland.Toxic weeds giant hogweed, tansy ragwort and poison-hemlock pose serious health risks to people and animals.Wetland and aquatic invaders purple and garden loosestrife, Brazilian elodea and policeman’s helmet clog waterways, crowd out native plants and harm fish and wildlife habitat.Grassland invaders spotted knapweed, orange hawkweed and milk thistle crowd out wildflowers and healthy forage species and degrade hay fields and rangeland. WASHINGTON’S NOXIOUS WEED LAW (RCW 17.10) protects natural and economic resources from the damage caused by noxious weeds. Weeds do not respect property boundaries and they affect everyone. Property owners and public land managers are required to control designated noxious weeds to prevent them from spreading. The highest priority is new invaders. There is still a chance to stop new weeds from establishing if everyone does their part. State weed law information can be found at nwcb.wa.gov.KING COUNTY’S NOXIOUS WEED LIST consists of all species set by the Washington State Noxious Weed Control Board (WAC 16-750) as Class A weeds, all Class B weeds state-designated for control in King County, and Class B and C species selected from the state list by the King County Noxious Weed Control Board. We also list additional, non-regulated invasive species for educational purposes. The list is reviewed annually and public input is encouraged.Learn more and report weeds online at kingcounty.gov/weedsSee inside for the 2019 KING COUNTY WEED LISTDepartment of Natural Resources and Parks
Water and Land Resources Division
Noxious Weed Control Program 1234512345
REGULATED CLASS C WEEDS: Class C weeds are generally widespread, but may be selected on a local level. The following Class C weeds have been selected by the King County Weed Board based on potential threats and feasibility of control. Property owners in King County are required to control these species.
FOOTNOTES:
1 Reported to be toxic to livestock and/or humans. Sources:
USDA Poisonous Plant Research Laboratory, USDA Natural
Resources Conservation Service, WA State Weed Board.
This list is for general information only and may not be
all-inclusive. Contact a medical professional for information
about symptoms and treatment.
2 Control of Scotch broom is required on the right-of-way of
King County’s section of SR-2 and on the I-90 right-of-way
between mile marker 34 and the King/Kittitas County line.
3 Brazilian elodea is designated for control throughout King
County except in Lake Washington, Lake Sammamish, Lake
Union, Lake Fenwick, Lake Doloff and the Sammamish River.
4 Control of Bohemian, Japanese, giant and Himalayan
knotweed (Polygonum xbohemicum, P. cuspidatum, P.
sachalinense, P. polystachyum) is required on the Green
River and its tributaries above the Auburn City Limits and
on the Cedar River and its tributaries above the Renton
City Limits (tributaries included are those defined as Type
S, F or N aquatic areas in KCC 21A.24.355). Control of
these invasive knotweed species is required up to the
ordinary high water mark (or to the top of the bank if the
ordinary high water mark cannot be identified) and in the
adjacent buffer area as specified in KCC 21A.24.358. This
requirement to control knotweed is contingent upon the
noxious weed program or program partners providing
knotweed control services in the selected area for affected
private land landowners who request assistance.
5 Non-native yellow-flowered hawkweeds (Hieracium species)
are consolidated into two listings by subgenus: meadow
(Pilosella) and wall (Hieracium). Control of species in the
meadow group is required in King County. Control of
species in the wall group is not required in King County
with the exception of European hawkweed (Hieracium
sabaudum).
6 Quarantine species. It is prohibited to transport, buy, sell,
offer for sale, or distribute plants, plant parts or seeds of
this species within the state of Washington. Noxious Weed
Seed and Plant Quarantine, WAC 16-752-600. Contact
Washington State Department of Agriculture for
complete list.
7 Control of poison-hemlock is required on public lands and
public right-of-way.
Department of Natural Resources and Parks
Water and Land Resources Division
Noxious Weed Control Program
206-477-9333 TTY Relay:711
kingcounty.gov/weeds
REGULATED CLASS A WEEDS: These weeds are
the highest priority in the state due to their significant potential
impact and limited distribution. Property owners throughout
Washington are required to eradicate Class A weeds.
REGULATED CLASS B WEEDS: Class B weeds are regulated in counties where they are limited in distribution or where they
are a local priority. The following Class B weeds have been designated for control in King County by the State Weed Board or selected by
the King County Weed Board. Property owners in King County are required to control these species.
2019 KING COUNTY NOXIOUS WEED LIST The King County Noxious Weed Control Board has adopted this Noxious Weed List in accordance with RCW 17.10 and WAC 16-750.
WEEDS OF CONCERN:
The following plant species are not listed as noxious weeds
under state law and property owners are not required
to control them. However, the King County Weed Board
recognizes these non-native plants as invasive, recommends
control or containment of existing populations, and
discourages new plantings. King County’s Critical Areas
Ordinance cites this list, formerly known as the Obnoxious
Weed List, as invasive vegetation that threatens native
ecosystems by displacing beneficial vegetation and degrading
wildlife and native plant habitat. The Noxious Weed Control
Program provides education and outreach services for these
weeds (as authorized by RCW 17.10.090).
LEGEND
Known to occur in King County
Historically present, but thought to be eradicated
NON-REGULATED NOXIOUS WEEDS: The following Class B and C weeds from the state noxious weed list also
impact the county, but are already widespread. Property owners in King County are not required to control these species, except
where noted, but control is recommended where feasible.
File name: 1902_9471m_noxWEEDlist2019-reprint.indd
Printed on recycled paper. Please recycle.
COMMON NAME SCIENTIFIC NAME
saltcedar 6 Tamarix ramosissima
shiny geranium 6 Geranium lucidum
spurge, leafy 1, 6 Euphorbia virgata
starthistle, Malta Centaurea melitensis
starthistle, yellow 1 Centaurea solstitialis
sulfur cinquefoil Potentilla recta
tansy ragwort 1, 6 Jacobaea vulgaris
thistle, musk 6 Carduus nutans
thistle, plumeless 6 Carduus acanthoides
thistle, Scotch 6 Onopordum acanthium
velvetleaf 6 Abutilon theophrasti
water primrose 6 Ludwigia hexapetala
white bryony 1 Bryonia alba
wild chervil 1, 6 Anthriscus sylvestris
yellow floatingheart 6 Nymphoides peltata
yellow nutsedge Cyperus esculentus
COMMON NAME SCIENTIFIC NAME
common crupina 6 Crupina vulgaris
cordgrass, common 6 Spartina anglica
cordgrass, dense flower 6 Spartina densiflora
cordgrass, saltmeadow 6 Spartina patens
cordgrass, smooth 6 Spartina alterniflora
dyers woad 6 Isatis tinctoria
eggleaf spurge 1, 6 Euphorbia oblongata
false brome 6 Brachypodium sylvaticum
floating primrose-willow 6 Ludwigia peploides
flowering-rush 6 Butomus umbellatus
French broom 1, 6 Genista monspessulana
garlic mustard 6 Alliaria petiolata
giant hogweed 1, 6 Heracleum mantegazzianum
goatsrue 1, 6 Galega officinalis
hydrilla 6 Hydrilla verticillata
Johnsongrass 1, 6 Sorghum halepense
knapweed, bighead 6 Centaurea macrocephala
knapweed, Vochin 6 Centaurea nigrescens
kudzu 6 Pueraria montana var. lobata
meadow clary 6 Salvia pratensis
oriental clematis 6 Clematis orientalis
purple starthistle 1, 6 Centaurea calcitrapa
reed sweetgrass 6 Glyceria maxima
ricefield bulrush 6 Schoenoplectus mucronatus
sage, clary 6 Salvia sclarea
sage, Mediterranean 6 Salvia aethiopis
silverleaf nightshade 1, 6 Solanum elaeagnifolium
small-flowered jewelweed Impatiens parviflora
Spanish broom 1, 6 Spartium junceum
Syrian beancaper 6 Zygophyllum fabago
Texas blueweed 6 Helianthus ciliaris
thistle, Italian 6 Carduus pycnocephalus
thistle, milk 1, 6 Silybum marianum
thistle, slenderflower 6 Carduus tenuiflorus
variable-leaf milfoil 6 Myriophyllum heterophyllum
wild four o’clock 6 Mirabilis nyctaginea
COMMON NAME SCIENTIFIC NAME
blueweed; viper’s bugloss 1, 6 Echium vulgare
Brazilian elodea 3, 6 Egeria densa
bugloss, annual Anchusa arvensis
bugloss, common 6 Anchusa officinalis
camelthorn Alhagi maurorum
common reed
(non-native genotypes)Phragmites australis
Dalmatian toadflax 6 Linaria dalmatica ssp.
dalmatica
European coltsfoot Tussilago farfara
fanwort 6 Cabomba caroliniana
gorse 6 Ulex europaeus
grass-leaved arrowhead 6 Sagittaria graminea
hairy willowherb 6 Epilobium hirsutum
hawkweeds; All non-native
species and hybrids of the
meadow subgenus 5, 6
Hieracium, subgenus
Pilosella
hawkweed, European 5, 6 Hieracium sabaudum
hawkweed, orange 6 Hieracium aurantiacum
hawkweed oxtongue Picris hieracioides
hoary alyssum Berteroa incana
houndstongue 1 Cynoglossum officinale
indigobush 6 Amorpha fruticosa
knapweed, black 6 Centaurea nigra
knapweed, brown 6 Centaurea jacea
knapweed, diffuse 6 Centaurea diffusa
knapweed, meadow 6 Centaurea x moncktonii
knapweed, Russian 1 Rhaponticum repens
knapweed, spotted 6 Centaurea stoebe
kochia 6 Bassia scoparia
loosestrife, garden 6 Lysimachia vulgaris
loosestrife, purple 6 Lythrum salicaria
parrotfeather 6 Myriophyllum aquaticum
perennial pepperweed 6 Lepidium latifolium
poison-hemlock 7 Conium maculatum
policeman’s helmet 6 Impatiens glandulifera
rush skeletonweed Chondrilla juncea
COMMON NAME SCIENTIFIC NAME CLASS
blackberry, evergreen Rubus laciniatus C
blackberry, Himalayan Rubus armeniacus C
butterfly bush 6 Buddleja davidii B
common barberry Berberis vulgaris C
common catsear Hypochaeris radicata C
common fennel Foeniculum vulgare
(except var. azoricum)
B
common groundsel 1 Senecio vulgaris C
common St. Johnswort Hypericum perforatum C
common tansy 1 Tanacetum vulgare C
common teasel Dipsacus fullonum C
curlyleaf pondweed Potamogeton crispus C
field bindweed Convolvulus arvensis C
fragrant waterlily Nymphaea odorata C
hairy whitetop 1 Lepidium appelianum C
hawkweeds; All non-
native species and
hybrids of the wall
subgenus 5, 6
Hieracium, subgenus
Hieracium B
hawthorn, English Crataegus monogyna C
herb-Robert Geranium robertianum B
hoary cress 1 Lepidium draba C
Italian arum Arum italicum C
ivy, English (four
cultivars only: ‘Baltica’,
‘Pittsburgh’,‘Star’,
and ‘Hibernica’) 1
Hedera helix ‘Baltica’
Hedera helix ‘Pittsburgh’
Hedera helix ‘Star’
Hedera hibernica ‘Hibernica’
C
jubata grass Cortaderia jubata C
knotweed, Bohemian 4, 6 Polygonum x bohemicum B
knotweed, giant 4, 6 Polygonum sachalinese B
knotweed, Himalayan 4, 6 Persicaria wallichii B
knotweed, Japanese 4, 6 Polygonum cuspidatum B
lesser celandine 6 Ficaria verna B
non-native cattails and
hybrids including narrow-
leaf and southern cattail
(does not include native
common cattail)
Typha angustifolia, T. x
glauca, T. domingensis
C
old man’s beard 1 Clematis vitalba C
oxeye daisy 6 Leucanthemum vulgare C
Pampas grass Cortaderia selloana C
perennial sowthistle Sonchus arvensis C
Ravenna grass Saccharum ravennae B
COMMON NAME SCIENTIFIC NAME
bird cherry Prunus avium
bishop’s weed Aegopodium podagraria
bittersweet nightshade 1 Solanum dulcamara
black locust Robinia pseudoacacia
buttercup, creeping 1 Ranunculus repens
buttercup, tall 1 Ranunculus acris
English holly 1 Ilex aquifolium
English laurel 1 Prunus laurocerasus
European mountain ash Sorbus aucuparia
hedge bindweed,
morning glory
Calystegia sepium
multiflora rose Rosa multiflora
rough chervil 1 Chaerophyllum temulum
silver lace vine Fallopia baldschuanica
syn. Polygonum aubertii
COMMON NAME SCIENTIFIC NAME CLASS
reed canarygrass Phalaris arundinacea B
Scotch broom 1, 2, 6 Cytisus scoparius B
spotted jewelweed Impatiens capensis C
spurge laurel 1 Daphne laureola B
thistle, bull Cirsium vulgare C
thistle, Canada Cirsium arvense C
tree-of-heaven 1 Ailanthus altissima C
ventenata Ventenata dubia C
watermilfoil, Eurasian 6 Myriophyllum spicatum B
watermilfoil hybrid 6,
(Eurasian x northern)
Myriophyllum spicatum x
M. sibiricum
C
wild carrot 6 Daucus carota C
yellow archangel 6 Lamiastrum galeobdolon B
yellowflag iris 1 Iris pseudacorus C
yellow toadflax Linaria vulgaris C
COMMON NAME SCIENTIFIC NAME
absinth wormwood 1 Artemesia absinthium
buffalobur 6 Solanum rostratum
CONTROL REQUIREDCONTROL RECOMMENDEDControl noxious weeds to protect people, livestock,
crops and the environment.