Natives by ZIP

Native plants recorded in your state and county

Native plants · Oregon

Native plants of Washington County

240 plant species are recorded as native to Oregon in Kew’s World Checklist of Vascular Plants and USDA PLANTS, and recorded in Washington County by USDA PLANTS. 170 of them have growing records you can filter by light, moisture, height and estimated cold hardiness. 5 more species are listed as both native and introduced and kept in a separate section.

County summary · USDA PLANTS and Kew WCVP

Washington County, Oregon

Native species
240 Typical Oregon county: 432 (median of 36 counties)
Garden-ready natives
170 Typical Oregon county: 311
Share by type (all 240 native species)
Percent of the 240 native species in each growth type
Tree 16% (38)
Shrub 8% (20)
Wildflower (forb) 50% (119)
Grass or grass-like 20% (48)
Vine 3% (6)
Fern 4% (9)

Wildflowers make up the largest share of the native list (50%), followed by grasses and grass-like plants (20%).

Recorded native ranges can include long-established populations that spread from gardens; check your state’s native plant society list for local guidance. How native status is decided.

ZIP codes mainly in this county fall in USDA hardiness zones 8b to 9a (2023 map).

The native plant list

Cold hardiness is estimated from each plant’s PLANTS minimum temperature. How we estimate it.

Garden-ready natives 170

Native species with PLANTS growing records (height, light, moisture, minimum temperature). “—” means PLANTS has no value.

Garden-ready native plants of Washington County, Oregon
PlantType HeightLight Water useHardy to
Alaska cedar Callitropsis nootkatensis Tree 75 ft Shade-tolerant Medium Zone 5a
American pokeweed Phytolacca americana Wildflower (forb) 7.3 ft Shade-tolerant Medium Zone 4a
American speedwell Veronica americana Wildflower (forb) 10 in Shade-tolerant High Zone 3b
American vetch Vicia americana Vine 1.3 ft Sun Low Zone 3b
arctic sweet coltsfoot Petasites frigidus Wildflower (forb) 10 in Sun–part shade High Zone 3b
arrowleaf ragwort Senecio triangularis Wildflower (forb) 4 ft Sun–part shade High Zone 4a
awlfruit sedge Carex stipata Grass or grass-like 3.5 ft Shade-tolerant Medium Zone 3b
beaked hazelnut Corylus cornuta Tree 15 ft Shade-tolerant Medium Zone 2b
bigflower agoseris Agoseris grandiflora Wildflower (forb) 1.8 ft Sun Medium Zone 6a
bigleaf maple Acer macrophyllum Tree 60 ft Sun–part shade Medium Zone 6a
bitter cherry Prunus emarginata Tree 80 ft Sun Medium Zone 5a
black hawthorn Crataegus douglasii Tree 15 ft Sun–part shade High Zone 2b
blue wildrye Elymus glaucus Grass or grass-like 3.3 ft Shade-tolerant Low Zone 3b
bluejoint Calamagrostis canadensis Grass or grass-like 4.9 ft Sun Medium Zone 4a
blunt spikerush Eleocharis obtusa Grass or grass-like 1.6 ft Sun Medium Zone 11a
Brewer's bittercress Cardamine breweri Wildflower (forb) 1.8 ft Shade-tolerant Medium Zone 5b
broadleaf arnica Arnica latifolia Wildflower (forb) 2 ft Sun–part shade High Zone 4a
broadleaf cattail Typha latifolia Wildflower (forb) 5 ft Sun–part shade High Zone 3b
broadleaf lupine Lupinus latifolius Wildflower (forb) 25 ft Shade-tolerant High Zone 5b
broom sedge Carex scoparia Grass or grass-like 2.5 ft Shade-tolerant High Zone 3b
California blackberry Rubus ursinus Shrub 2 ft Sun Medium Zone 8a
California false hellebore Veratrum californicum Wildflower (forb) 6 ft Shade-tolerant High Zone 3b
California fescue Festuca californica Grass or grass-like 4 ft Sun Medium Zone 8a
California huckleberry Vaccinium ovatum Shrub 8 ft Shade-tolerant Low Zone 8a
California oatgrass Danthonia californica Grass or grass-like 2 ft Sun Medium Zone 9a
California poppy Eschscholzia californica Wildflower (forb) 1.2 ft Sun–part shade Low Zone 8a
Canadian waterweed Elodea canadensis Wildflower (forb) — Sun High Zone 4a
Cascade barberry Mahonia nervosa Shrub 2 ft Shade-tolerant Low Zone 5b
Cascara buckthorn Frangula purshiana Tree 35 ft Shade-tolerant Medium Zone 7a
chamisso sedge Carex pachystachya Grass or grass-like 3.5 ft Shade-tolerant Medium Zone 3b
chokecherry Prunus virginiana Tree 25 ft Sun Medium Zone 3a
cluster rose Rosa pisocarpa Shrub 3 ft Sun — Zone 5a
coastal monkeyflower Mimulus dentatus Wildflower (forb) 1.5 ft Shade-tolerant Medium Zone 7b
Columbia brome Bromus vulgaris Grass or grass-like 1 ft Shade-tolerant Low Zone 5a
common cowparsnip Heracleum maximum Wildflower (forb) 8 ft Sun High Zone 3b
common duckweed Lemna minor Wildflower (forb) — Sun High Zone 3b
common rush Juncus effusus Grass or grass-like 6.6 ft Sun Medium Zone 3b
common selfheal Prunella vulgaris Wildflower (forb) 1.5 ft Sun–part shade Medium Zone 3b
common snowberry Symphoricarpos albus Shrub 3 ft Sun Medium Zone 3b
common spikerush Eleocharis palustris Grass or grass-like 1.3 ft Sun High Zone 3b
copperbush Elliottia pyroliflora Shrub 5 ft — — Zone 5a
cosmopolitan bulrush Bolboschoenus maritimus Grass or grass-like 3.2 ft Sun Medium Zone 5a
curvepod yellowcress Rorippa curvisiliqua Wildflower (forb) 1 ft Shade-tolerant High Zone 12b
deer fern Blechnum spicant Fern 3.5 ft Sun–part shade High Zone 6b
devil's beggartick Bidens frondosa Wildflower (forb) 4 ft Sun–part shade Medium Zone 12a
Douglas aster Symphyotrichum subspicatum Wildflower (forb) 4 in Sun–part shade High Zone 6b
Douglas-fir Pseudotsuga menziesii Tree 200 ft Sun–part shade Medium Zone 4a
drooping woodreed Cinna latifolia Grass or grass-like 4.5 ft Sun–part shade High Zone 3b
dwarf rose Rosa gymnocarpa Shrub 3 ft Shade-tolerant Medium Zone 5b
fernleaf biscuitroot Lomatium dissectum Wildflower (forb) 15 ft Sun–part shade Low Zone 8a
field horsetail Equisetum arvense Fern 11 in Sun–part shade High Zone 3a
fireweed Chamerion angustifolium Wildflower (forb) 5.5 ft Sun–part shade High Zone 3b
flatstem pondweed Potamogeton zosteriformis Wildflower (forb) — Sun High Zone 3b
fowl bluegrass Poa palustris Grass or grass-like 4 ft Sun–part shade Medium Zone 3b
fringed grass of Parnassus Parnassia fimbriata Wildflower (forb) 1.2 ft Sun–part shade High Zone 4b
Geyer willow Salix geyeriana Tree 15 ft Shade-tolerant High Zone 3b
giant chinquapin Chrysolepis chrysophylla Tree 100 ft Shade-tolerant Medium Zone 4a
glaucus willowherb Epilobium glaberrimum Wildflower (forb) 2 ft Shade-tolerant Medium Zone 6b
grand fir Abies grandis Tree 150 ft Shade-tolerant Medium Zone 4a
greater creeping spearwort Ranunculus flammula Wildflower (forb) 1.5 ft Shade-tolerant High Zone 4a
hairy manzanita Arctostaphylos columbiana Tree 6 ft Sun–part shade Low Zone 8a
harsh Indian paintbrush Castilleja hispida Wildflower (forb) 1.5 ft Sun Low Zone 5a
heartleaf arnica Arnica cordifolia Wildflower (forb) 1.5 ft Shade-tolerant High Zone 4b
Henderson's sedge Carex hendersonii Grass or grass-like 3 ft Shade-tolerant Medium Zone 6b
hollyleaved barberry Mahonia aquifolium Shrub 8 ft Shade-tolerant Low Zone 3a
Idaho blue-eyed grass Sisyrinchium idahoense Wildflower (forb) 1.7 ft Shade-tolerant High Zone 3b
Idaho fescue Festuca idahoensis Grass or grass-like 2 ft Sun–part shade Medium Zone 3b
Indian plum Oemleria cerasiformis Tree 5 ft Sun–part shade — Zone 10a
Indianhemp Apocynum cannabinum Wildflower (forb) 3.3 ft Sun–part shade High Zone 3a
knotgrass Paspalum distichum Grass or grass-like 11 in Sun High Zone 6a
lambstongue ragwort Senecio integerrimus Wildflower (forb) 1.1 ft Sun–part shade Medium Zone 3b
largeflower hawksbeard Crepis occidentalis Wildflower (forb) 11 in Sun Low Zone 5a
largeleaf avens Geum macrophyllum Wildflower (forb) 2 ft Shade-tolerant Medium Zone 4a
leafy pea Lathyrus polyphyllus Vine 2.7 ft Sun–part shade Medium Zone 7b
leafy pondweed Potamogeton foliosus Wildflower (forb) — Sun High Zone 3b
Lewis' mock orange Philadelphus lewisii Shrub 12 ft Sun Low Zone 8a
little western bittercress Cardamine oligosperma Wildflower (forb) 1.7 ft Shade-tolerant Medium Zone 5a
livid sedge Carex livida Grass or grass-like 1 ft Sun — Zone 1a
longleaf starwort Stellaria longifolia Wildflower (forb) 1.5 ft Shade-tolerant High Zone 3b
maiden blue eyed Mary Collinsia parviflora Wildflower (forb) 1 ft Shade-tolerant Medium Zone 4a
marsh seedbox Ludwigia palustris Wildflower (forb) 2 in Sun High Zone 4a
meadow barley Hordeum brachyantherum Grass or grass-like 2 ft Sun Medium Zone 3a
Mertens' sedge Carex mertensii Grass or grass-like 3.5 ft Shade-tolerant Medium Zone 4b
miner's lettuce Claytonia perfoliata Wildflower (forb) 1 ft Shade-tolerant Medium Zone 12b
narrowleaf willow Salix exigua Tree 10 ft Sun–part shade High Zone 3b
needle spikerush Eleocharis acicularis Grass or grass-like 8 in Sun Medium Zone 5a
noble fir Abies procera Tree 230 ft Sun–part shade Low Zone 5a
nodding beggartick Bidens cernua Wildflower (forb) 3.2 ft Sun–part shade High Zone 12a
Nootka rose Rosa nutkana Shrub 10 ft Shade-tolerant High Zone 8a
northwest sandbar willow Salix sessilifolia Tree 20 ft Sun–part shade Medium Zone 4a
oceanspray Holodiscus discolor Shrub 12 ft Sun High Zone 8a
Oregon ash Fraxinus latifolia Tree 70 ft Sun–part shade Medium Zone 6b
Oregon crab apple Malus fusca Tree 15 ft Sun–part shade — Zone 10a
Oregon geranium Geranium oreganum Wildflower (forb) 3 ft Shade-tolerant High Zone 8a
Oregon white oak Quercus garryana Tree 80 ft Sun Low Zone 4a
Pacific bleeding heart Dicentra formosa Wildflower (forb) 1.5 ft Shade-tolerant Low Zone 5a
Pacific dogwood Cornus nuttallii Tree 50 ft Shade-tolerant Medium Zone 4b
Pacific madrone Arbutus menziesii Tree 80 ft Sun–part shade Low Zone 8b
Pacific ninebark Physocarpus capitatus Shrub 8 ft Sun Low Zone 4a
Pacific rhododendron Rhododendron macrophyllum Tree 15 ft Sun–part shade High Zone 8a
Pacific silver fir Abies amabilis Tree 165 ft Shade-tolerant Medium Zone 4b
Pacific yew Taxus brevifolia Tree 40 ft Shade-tolerant Low Zone 5b
panicled bulrush Scirpus microcarpus Grass or grass-like 5.5 ft Sun Medium Zone 3b
Pennsylvania bittercress Cardamine pensylvanica Wildflower (forb) 1.5 ft Shade-tolerant Medium Zone 4a
Philadelphia fleabane Erigeron philadelphicus Wildflower (forb) 2.8 ft Sun–part shade Medium Zone 4b
plantainleaf buttercup Ranunculus alismifolius Wildflower (forb) 2 ft Sun–part shade High Zone 4a
ponderosa pine Pinus ponderosa Tree 223 ft Sun Medium Zone 3b
Port Orford cedar Chamaecyparis lawsoniana Tree 200 ft Shade-tolerant Medium Zone 6a
poverty rush Juncus tenuis Grass or grass-like 1.5 ft Sun–part shade Medium Zone 3b
prickly currant Ribes lacustre Shrub 3 ft Shade-tolerant — Zone 1a
quaking aspen Populus tremuloides Tree 65 ft Sun High Zone 1a
red alder Alnus rubra Tree 90 ft Sun High Zone 5a
red elderberry Sambucus racemosa Tree 18 ft Sun–part shade High Zone 4a
red huckleberry Vaccinium parvifolium Shrub 12 ft Shade-tolerant Low Zone 6a
redflower currant Ribes sanguineum Shrub 12 ft Sun–part shade Medium Zone 8a
redosier dogwood Cornus sericea Tree 12 ft Sun High Zone 3b
redroot flatsedge Cyperus erythrorhizos Grass or grass-like 2.5 ft Sun Medium Zone 11a
redstem ceanothus Ceanothus sanguineus Shrub 10 ft Sun–part shade High Zone 6a
reed canarygrass Phalaris arundinacea Grass or grass-like 5 ft Sun High Zone 3b
rice cutgrass Leersia oryzoides Grass or grass-like 4.9 ft Sun High Zone 4a
river bulrush Bolboschoenus fluviatilis Grass or grass-like 6.6 ft Sun Medium Zone 3b
rose spirea Spiraea douglasii Shrub 7 ft Sun Low Zone 5a
Rydberg's penstemon Penstemon rydbergii Wildflower (forb) 3 ft Sun Low Zone 3b
salal Gaultheria shallon Shrub 6 ft Shade-tolerant High Zone 8a
salmonberry Rubus spectabilis Vine 12 ft Sun–part shade Medium Zone 4a
sanddune wallflower Erysimum capitatum Wildflower (forb) 2.5 ft Sun Medium Zone 4b
Saskatoon serviceberry Amelanchier alnifolia Tree 15 ft Sun–part shade Medium Zone 1a
Scouler's willow Salix scouleriana Tree 50 ft Sun–part shade High Zone 6a
seep monkeyflower Mimulus guttatus Wildflower (forb) 2.5 ft Shade-tolerant High Zone 3b
shortawn foxtail Alopecurus aequalis Grass or grass-like 2.5 ft Sun–part shade High Zone 3b
Siberian springbeauty Claytonia sibirica Wildflower (forb) 1.4 ft Shade-tolerant Medium Zone 3a
silky lupine Lupinus sericeus Wildflower (forb) 6 ft Sun Low Zone 4b
Sitka willow Salix sitchensis Tree 23 ft Sun High Zone 5b
slender cinquefoil Potentilla gracilis Wildflower (forb) 2.4 ft Sun Low Zone 3a
slender hairgrass Deschampsia elongata Grass or grass-like 3 ft Sun Low Zone 3b
slough sedge Carex obnupta Grass or grass-like 3 ft Sun–part shade High Zone 7a
small camas Camassia quamash Wildflower (forb) 2.3 ft Shade-tolerant High Zone 4b
small enchanter's nightshade Circaea alpina Wildflower (forb) 11 in Shade-tolerant Medium Zone 3b
smallflowered woodrush Luzula parviflora Grass or grass-like 2 ft Shade-tolerant High Zone 4a
spike bentgrass Agrostis exarata Grass or grass-like 3 ft Sun Medium Zone 3b
spreading phlox Phlox diffusa Wildflower (forb) 6 in Shade-tolerant Low Zone 6a
star sedge Carex echinata Grass or grass-like 1.5 ft Sun–part shade High Zone 3b
sticky cinquefoil Potentilla glandulosa Wildflower (forb) 1.5 ft Sun–part shade Low Zone 4a
swamp smartweed Polygonum hydropiperoides Wildflower (forb) — Sun Medium Zone 10b
swordleaf rush Juncus ensifolius Grass or grass-like 2 ft Sun–part shade High Zone 3b
tall trisetum Trisetum canescens Grass or grass-like 3.5 ft Sun–part shade Medium Zone 4a
tapertip rush Juncus acuminatus Grass or grass-like 3 ft Sun–part shade High Zone 4a
teal lovegrass Eragrostis hypnoides Grass or grass-like 4 in Sun High Zone 3b
thimbleberry Rubus parviflorus Shrub 4 ft Sun–part shade High Zone 4b
threepetal bedstraw Galium trifidum Vine 10 in Sun–part shade High Zone 3b
toad rush Juncus bufonius Grass or grass-like 1 ft Sun Medium Zone 12a
Torrey's rush Juncus torreyi Grass or grass-like 3.1 ft Sun Medium Zone 3b
toughleaf iris Iris tenax Wildflower (forb) 1.5 ft Shade-tolerant Medium Zone 6a
tufted hairgrass Deschampsia cespitosa Grass or grass-like 3.4 ft Sun Low Zone 3b
twinberry honeysuckle Lonicera involucrata Shrub 10 ft Shade-tolerant High Zone 3a
twoheaded water-starwort Callitriche heterophylla Wildflower (forb) — Sun High Zone 4a
vernal water-starwort Callitriche palustris Wildflower (forb) 10 in Sun Medium Zone 4a
vine maple Acer circinatum Tree 20 ft Shade-tolerant Medium Zone 6a
water knotweed Polygonum amphibium Wildflower (forb) 1 in Sun High Zone 5a
western columbine Aquilegia formosa Wildflower (forb) 3 ft Shade-tolerant Medium Zone 5a
western fescue Festuca occidentalis Grass or grass-like 3 ft Shade-tolerant Low Zone 3a
western hemlock Tsuga heterophylla Tree 170 ft Shade-tolerant Medium Zone 5a
western pearly everlasting Anaphalis margaritacea Wildflower (forb) 3 ft Sun–part shade Medium Zone 3a
western redcedar Thuja plicata Tree 150 ft Shade-tolerant Medium Zone 4a
western sweetroot Osmorhiza occidentalis Wildflower (forb) 4 ft Shade-tolerant Medium Zone 3b
western swordfern Polystichum munitum Fern 3.5 ft Shade-tolerant High Zone 4a
western water hemlock Cicuta douglasii Wildflower (forb) 6 ft Sun High Zone 4b
western waterleaf Hydrophyllum occidentale Wildflower (forb) 1.5 ft Shade-tolerant Medium Zone 5b
white hawkweed Hieracium albiflorum Wildflower (forb) 3 ft Sun–part shade Low Zone 4a
whitebark raspberry Rubus leucodermis Vine 1 ft Sun Medium Zone 8a

Other native species recorded here 70

PLANTS has no growing records for these, so light, moisture, height and zone filters cannot include them. Many are wild species seldom sold by nurseries.

  • Aleutian maidenhair Adiantum aleuticum
  • American bird's-foot trefoil Lotus unifoliolatus
  • American mannagrass Glyceria grandis
  • American rockbrake Cryptogramma acrostichoides
  • American sloughgrass Beckmannia syzigachne
  • American yellowrocket Barbarea orthoceras
  • arroyo willow Salix lasiolepis
  • bastard toadflax Comandra umbellata
  • bay forget-me-not Myosotis laxa
  • bigleaf lupine Lupinus polyphyllus
  • boreal starwort Stellaria borealis
  • brittle bladderfern Cystopteris fragilis
  • brook cinquefoil Potentilla rivalis
  • Carolina geranium Geranium carolinianum
  • clammy hedgehyssop Gratiola neglecta
  • coast tarweed Madia sativa
  • common woodrush Luzula multiflora
  • cottonbatting plant Pseudognaphalium stramineum
  • curlytop knotweed Polygonum lapathifolium
  • dune willow Salix hookeriana
  • European bur-reed Sparganium emersum
  • fairy slipper Calypso bulbosa
  • feathery false lily of the valley Maianthemum racemosum
  • fragrant bedstraw Galium triflorum
  • fringed willowherb Epilobium ciliatum
  • giant red Indian paintbrush Castilleja miniata
  • heartleaf twayblade Listera cordata
  • hooded coralroot Corallorhiza striata
  • hookedspur violet Viola adunca
  • Howell's pussytoes Antennaria howellii
  • Indianpipe Monotropa uniflora
  • lanceleaf figwort Scrophularia lanceolata
  • largeleaf sandwort Moehringia macrophylla
  • lowland rotala Rotala ramosior
  • manyflower stickseed Hackelia floribunda
  • meadow deathcamas Zigadenus venenosus
  • meadow sedge Carex praticola
  • meadow zizia Zizia aptera
  • Mexican Mosquito Fern Azolla microphylla
  • milkflower willowherb Epilobium lactiflorum
  • mountain tarweed Madia glomerata
  • muskflower Mimulus moschatus
  • narrowleaf minerslettuce Montia linearis
  • neckweed Veronica peregrina
  • needleleaf navarretia Navarretia intertexta
  • northern water plantain Alisma triviale
  • pale false mannagrass Torreyochloa pallida
  • pinesap Monotropa hypopitys
  • red baneberry Actaea rubra
  • roundleaf sundew Drosera rotundifolia
  • running clubmoss Lycopodium clavatum
  • Scouler's popcornflower Plagiobothrys scouleri
  • sixweeks fescue Vulpia octoflora
  • slender bog orchid Platanthera stricta
  • slender phlox Microsteris gracilis
  • spreading dogbane Apocynum androsaemifolium
  • starry false lily of the valley Maianthemum stellatum
  • summer coralroot Corallorhiza maculata
  • sweetcicely Osmorhiza berteroi
  • tall annual willowherb Epilobium brachycarpum
  • tall blue lettuce Lactuca biennis
  • threadleaf crowfoot Ranunculus trichophyllus
  • twinflower Linnaea borealis
  • Virginia strawberry Fragaria virginiana
  • western marsh cudweed Gnaphalium palustre
  • western oakfern Gymnocarpium dryopteris
  • western rattlesnake plantain Goodyera oblongifolia
  • witchgrass Panicum capillare
  • woodland strawberry Fragaria vesca
  • yellowseed false pimpernel Lindernia dubia
Also listed as native and introduced here 5

PLANTS labels these species both native and introduced in this state: some forms are native and others were brought in from elsewhere. Most gardeners should choose plants from the main list.

  • annual ragweedAmbrosia artemisiifolia
  • bride's feathersAruncus dioicus
  • claspleaf twistedstalkStreptopus amplexifolius
  • hedge false bindweedCalystegia sepium
  • Kentucky bluegrassPoa pratensis

Compared with Oregon

The typical county is the median of the 36 Oregon counties with PLANTS county records; the statewide figure counts every species native anywhere in the state. More species is not better or worse: counties differ in size, habitat and how thoroughly they have been surveyed.

Native species counts, Washington County and Oregon
MeasureWashington CountyTypical countyStatewide
Native species 240 432 1,058
Garden-ready natives 170 311 683
Tree 38 — 87
Shrub 20 — 115
Wildflower (forb) 119 — 567
Grass or grass-like 48 — 232
Vine 6 — 18
Fern 9 — 39

Neighboring counties

Counties that share a ZIP code with Washington County.

Look up another ZIP

Matches your ZIP to the county it mostly lies in, then lists the plants recorded as native to your state (Kew’s World Checklist and USDA PLANTS) and recorded in that county by USDA PLANTS.

Source & data date

Source
USDA NRCS PLANTS Database: county distribution records, native status and plant characteristics. CC0 (public domain dedication, per the data.gov catalog record).
Kew’s World Checklist of Vascular Plants (WCVP): native or introduced status by state. CC BY 3.0.
USGS US-RIIS (ver. 2.0): species listed as introduced are excluded. CC0.
Citation
USDA, NRCS. 2026. The PLANTS Database (https://plants.usda.gov, 11/04/2026). National Plant Data Team, Greensboro, NC USA.
Govaerts R. (ed.) (2026). WCVP: World Checklist of Vascular Plants. Facilitated by the Royal Botanic Gardens, Kew. Data file dated 2026-06-04, http://sftp.kew.org/pub/data-repositories/WCVP/ (retrieved 2026-11-04). Paper: Govaerts R. et al. (2021) The World Checklist of Vascular Plants, a continuously updated resource for exploring global plant diversity. Scientific Data 8, 215.
Data date
Retrieved from PLANTS on November 4, 2026; WCVP data file dated June 4, 2026.
Zones
USDA Plant Hardiness Zone Map (2023) ZIP table: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed November 3, 2026. Plant zones on this site are our estimate, not the official map.
Scope
Washington County (county FIPS 41067), Oregon. 240 native species from PLANTS county distribution records; garden-ready = species with a PLANTS characteristics record.
Method
A species is listed when it is recorded as native to the state in Kew’s World Checklist of Vascular Plants and USDA PLANTS, and recorded in the county by USDA PLANTS. Species PLANTS labels both native and introduced are listed separately. Full method · All sources

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