Native plants · Idaho

Native plants of Washington County

267 plant species are recorded as native to Idaho in Kew’s World Checklist of Vascular Plants and USDA PLANTS, and recorded in Washington County by USDA PLANTS. 192 of them have growing records you can filter by light, moisture, height and estimated cold hardiness. 3 more species are listed as both native and introduced and kept in a separate section.

County summary · USDA PLANTS and Kew WCVP

Washington County, Idaho

Native species: 267 Typical Idaho county: 302 (median of 44 counties)
Garden-ready natives: 192 Typical Idaho county: 211
Share by type (all 267 native species): Percent of the 267 native species in each growth type

Tree 12% (32)
Shrub 10% (28)
Wildflower (forb) 58% (154)
Grass or grass-like 16% (44)
Vine 2% (6)
Fern 1% (3)

Wildflowers make up the largest share of the native list (58%), followed by grasses and grass-like plants (16%).

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 6a to 7a (2023 map).

The native plant list

Garden-ready natives 192

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

Garden-ready native plants of Washington County, Idaho
Plant	Type	Height	Light	Water use	Hardy to
American licorice Glycyrrhiza lepidota	Wildflower (forb)	4 ft	Sun–part shade	High	Zone 3b
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
Anderson's larkspur Delphinium andersonii	Wildflower (forb)	2 ft	Shade-tolerant	Low	Zone 5b
annual hairgrass Deschampsia danthonioides	Grass or grass-like	1.5 ft	Sun–part shade	Medium	Zone 12b
antelope bitterbrush Purshia tridentata	Shrub	6 ft	Sun–part shade	Low	Zone 3b
arrowleaf ragwort Senecio triangularis	Wildflower (forb)	4 ft	Sun–part shade	High	Zone 4a
arumleaf arrowhead Sagittaria cuneata	Wildflower (forb)	2.6 ft	Sun	Medium	Zone 4a
awlfruit sedge Carex stipata	Grass or grass-like	3.5 ft	Shade-tolerant	Medium	Zone 3b
ballhead waterleaf Hydrophyllum capitatum	Wildflower (forb)	1 ft	Shade-tolerant	High	Zone 4b
basalt milkvetch Astragalus filipes	Wildflower (forb)	2 ft	Sun	Low	Zone 5a
basin wildrye Leymus cinereus	Grass or grass-like	5 ft	Sun	High	Zone 3a
beardless wildrye Leymus triticoides	Grass or grass-like	3 ft	Sun	High	Zone 3a
big sagebrush Artemisia tridentata	Tree	4 ft	Sun	Medium	Zone 3a
bigflower agoseris Agoseris grandiflora	Wildflower (forb)	1.8 ft	Sun	Medium	Zone 6a
bigseed biscuitroot Lomatium macrocarpum	Wildflower (forb)	6 in	Sun	Low	Zone 4b
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 Mountain buckwheat Eriogonum strictum	Wildflower (forb)	2.2 ft	Sun	Low	Zone 5a
bluebunch wheatgrass Pseudoroegneria spicata	Grass or grass-like	3 ft	Sun	Low	Zone 3b
boxelder Acer negundo	Tree	60 ft	Shade-tolerant	Medium	Zone 2b
Brown's peony Paeonia brownii	Wildflower (forb)	1.5 ft	Sun–part shade	Medium	Zone 5a
bushy bird's beak Cordylanthus ramosus	Wildflower (forb)	1 ft	Sun–part shade	Medium	Zone 12b
Canada goldenrod Solidago canadensis	Wildflower (forb)	3.5 ft	Sun	Medium	Zone 3a
Canadian milkvetch Astragalus canadensis	Wildflower (forb)	6 in	Sun	Medium	Zone 3b
Canby's biscuitroot Lomatium canbyi	Wildflower (forb)	10 in	Sun	Low	Zone 4b
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
cloaked bulrush Scirpus pallidus	Grass or grass-like	5 ft	Sun	Medium	Zone 3b
clustered field sedge Carex praegracilis	Grass or grass-like	2 ft	Sun–part shade	Medium	Zone 3b
Columbia needlegrass Achnatherum nelsonii	Grass or grass-like	3 ft	Sun	Low	Zone 4b
common duckweed Lemna minor	Wildflower (forb)	—	Sun	High	Zone 3b
common sneezeweed Helenium autumnale	Wildflower (forb)	4.9 ft	Sun	Medium	Zone 3a
common snowberry Symphoricarpos albus	Shrub	3 ft	Sun	Medium	Zone 3b
creeping barberry Mahonia repens	Shrub	2 ft	Shade-tolerant	Medium	Zone 5a
curl-leaf mountain mahogany Cercocarpus ledifolius	Tree	20 ft	Sun–part shade	Low	Zone 2b
cursed buttercup Ranunculus sceleratus	Wildflower (forb)	2 ft	Shade-tolerant	High	Zone 12b
desert centaury Centaurium exaltatum	Wildflower (forb)	1.5 ft	Sun	Medium	Zone 12b
desert yellow fleabane Erigeron linearis	Wildflower (forb)	1 ft	Sun	Low	Zone 5a
Douglas-fir Pseudotsuga menziesii	Tree	200 ft	Sun–part shade	Medium	Zone 4a
Douglas' grasswidow Olsynium douglasii	Wildflower (forb)	1 ft	Sun	Medium	Zone 5a
Eaton's fleabane Erigeron eatonii	Wildflower (forb)	10 in	Sun	Low	Zone 5b
Engelmann spruce Picea engelmannii	Tree	120 ft	Shade-tolerant	Medium	Zone 2a
fernleaf biscuitroot Lomatium dissectum	Wildflower (forb)	15 ft	Sun–part shade	Low	Zone 8a
fireweed Chamerion angustifolium	Wildflower (forb)	5.5 ft	Sun–part shade	High	Zone 3b
foothill deathcamas Zigadenus paniculatus	Wildflower (forb)	1.6 ft	Sun	Medium	Zone 4a
fowl mannagrass Glyceria striata	Grass or grass-like	5.7 ft	Shade-tolerant	Medium	Zone 3b
fox sedge Carex vulpinoidea	Grass or grass-like	3.2 ft	Sun–part shade	Medium	Zone 3b
freckled milkvetch Astragalus lentiginosus	Shrub	1.4 ft	Sun	Low	Zone 4b
Gairdner's beardtongue Penstemon gairdneri	Wildflower (forb)	1 ft	Sun	Low	Zone 4b
Geyer's sedge Carex geyeri	Grass or grass-like	1.5 ft	Sun–part shade	Low	Zone 4b
giant goldenrod Solidago gigantea	Wildflower (forb)	8.2 ft	Sun–part shade	Medium	Zone 4a
golden spiderflower Cleome platycarpa	Wildflower (forb)	2 ft	Sun	Medium	Zone 12b
golden tickseed Coreopsis tinctoria	Wildflower (forb)	3 ft	Sun–part shade	High	Zone 12b
grand fir Abies grandis	Tree	150 ft	Shade-tolerant	Medium	Zone 4a
gray alder Alnus incana	Tree	25 ft	Sun–part shade	High	Zone 4a
greasewood Sarcobatus vermiculatus	Shrub	10 ft	Sun	Low	Zone 3b
Greene's mountain ash Sorbus scopulina	Tree	12 ft	Sun–part shade	Medium	Zone 7a
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
Hooker's balsamroot Balsamorhiza hookeri	Wildflower (forb)	1 ft	Sun–part shade	Medium	Zone 5b
Indian ricegrass Achnatherum hymenoides	Grass or grass-like	2 ft	Sun	Low	Zone 3a
Indianhemp Apocynum cannabinum	Wildflower (forb)	3.3 ft	Sun–part shade	High	Zone 3a
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
largeflower triteleia Triteleia grandiflora	Wildflower (forb)	2 ft	Sun–part shade	Medium	Zone 4a
largehead clover Trifolium macrocephalum	Wildflower (forb)	2 ft	Sun–part shade	Low	Zone 12b
largeleaf avens Geum macrophyllum	Wildflower (forb)	2 ft	Shade-tolerant	Medium	Zone 4a
Lewis flax Linum lewisii	Wildflower (forb)	2.5 ft	Sun	Medium	Zone 3b
Lewis' mock orange Philadelphus lewisii	Shrub	12 ft	Sun	Low	Zone 8a
little barley Hordeum pusillum	Grass or grass-like	1.2 ft	Sun	Medium	Zone 10b
little sagebrush Artemisia arbuscula	Shrub	2 ft	Sun	Low	Zone 3a
longleaf phlox Phlox longifolia	Wildflower (forb)	1.2 ft	Sun–part shade	Low	Zone 6a
low pussytoes Antennaria dimorpha	Wildflower (forb)	4 in	Sun–part shade	Low	Zone 3b
MacKenzie's willow Salix prolixa	Tree	45 ft	Sun	Low	Zone 2a
maiden blue eyed Mary Collinsia parviflora	Wildflower (forb)	1 ft	Shade-tolerant	Medium	Zone 4a
mallow ninebark Physocarpus malvaceus	Shrub	15 ft	Sun	Low	Zone 4a
Missouri goldenrod Solidago missouriensis	Wildflower (forb)	3 ft	Sun–part shade	Low	Zone 3b
Modoc hawksbeard Crepis modocensis	Wildflower (forb)	1.4 ft	Sun	Low	Zone 4b
mountain brome Bromus marginatus	Grass or grass-like	4 ft	Sun	High	Zone 4b
mule-ears Wyethia amplexicaulis	Wildflower (forb)	2.5 ft	Sun	Medium	Zone 3b
Munro's globemallow Sphaeralcea munroana	Wildflower (forb)	2.5 ft	Sun	Low	Zone 4b
muttongrass Poa fendleriana	Grass or grass-like	2 ft	Sun	Low	Zone 3b
narrowleaf willow Salix exigua	Tree	10 ft	Sun–part shade	High	Zone 3b
nineleaf biscuitroot Lomatium triternatum	Wildflower (forb)	2.2 ft	Sun–part shade	Medium	Zone 4a
nodding microseris Microseris nutans	Wildflower (forb)	2 ft	Shade-tolerant	Medium	Zone 4b
Nootka rose Rosa nutkana	Shrub	10 ft	Shade-tolerant	High	Zone 8a
northern bedstraw Galium boreale	Wildflower (forb)	3 ft	Sun–part shade	Medium	Zone 4a
northern black currant Ribes hudsonianum	Shrub	5 ft	Sun–part shade	High	Zone 4a
northwestern Indian paintbrush Castilleja angustifolia	Wildflower (forb)	2.5 ft	Shade-tolerant	Medium	Zone 4a
oneflower helianthella Helianthella uniflora	Wildflower (forb)	2 ft	Sun–part shade	Low	Zone 5a
oniongrass Melica bulbosa	Grass or grass-like	1.8 ft	Sun–part shade	Low	Zone 3a
Oregon checkerbloom Sidalcea oregana	Wildflower (forb)	4.5 ft	Shade-tolerant	High	Zone 3b
Pacific onion Allium validum	Wildflower (forb)	2 ft	Sun–part shade	High	Zone 5b
Pacific yew Taxus brevifolia	Tree	40 ft	Shade-tolerant	Low	Zone 5b
pale agoseris Agoseris glauca	Shrub	1 ft	Sun	Medium	Zone 4a
pale evening primrose Oenothera pallida	Wildflower (forb)	2 ft	Sun	Low	Zone 3b
peachleaf willow Salix amygdaloides	Tree	60 ft	Sun	High	Zone 4a
pearly pussytoes Antennaria anaphaloides	Wildflower (forb)	2.5 ft	Sun–part shade	Medium	Zone 4a
Pennsylvania bittercress Cardamine pensylvanica	Wildflower (forb)	1.5 ft	Shade-tolerant	Medium	Zone 4a
pinkfairies Clarkia pulchella	Wildflower (forb)	2 ft	Sun–part shade	Medium	Zone 12a
pipsissewa Chimaphila umbellata	Shrub	1.5 ft	Shade-tolerant	Low	Zone 3b
plains pricklypear Opuntia polyacantha	Shrub	2 ft	Sun	Low	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
poverty rush Juncus tenuis	Grass or grass-like	1.5 ft	Sun–part shade	Medium	Zone 3b
prairie fleabane Erigeron strigosus	Wildflower (forb)	3 ft	Sun	Medium	Zone 4b
prickly currant Ribes lacustre	Shrub	3 ft	Shade-tolerant	—	Zone 1a
red elderberry Sambucus racemosa	Tree	18 ft	Sun–part shade	High	Zone 4a
redosier dogwood Cornus sericea	Tree	12 ft	Sun	High	Zone 3b
rock buckwheat Eriogonum sphaerocephalum	Shrub	1 ft	Sun	Low	Zone 5a
Rocky Mountain iris Iris missouriensis	Wildflower (forb)	1 ft	Sun–part shade	High	Zone 4b
Rocky Mountain maple Acer glabrum	Tree	30 ft	Sun–part shade	Low	Zone 3a
Ross' sedge Carex rossii	Grass or grass-like	1 ft	Sun–part shade	Medium	Zone 4a
roundleaf alumroot Heuchera cylindrica	Wildflower (forb)	6 ft	Sun–part shade	Low	Zone 6a
royal penstemon Penstemon speciosus	Wildflower (forb)	2.5 ft	Sun	Low	Zone 4a
rubber rabbitbrush Ericameria nauseosa	Shrub	4 ft	Sun	Medium	Zone 3b
rush pussytoes Antennaria luzuloides	Wildflower (forb)	2 ft	Sun	Medium	Zone 4a
sagebrush buttercup Ranunculus glaberrimus	Wildflower (forb)	6 in	Sun	High	Zone 3a
sagebrush mariposa lily Calochortus macrocarpus	Wildflower (forb)	1.8 ft	Sun	Low	Zone 5a
saltgrass Distichlis spicata	Grass or grass-like	1.1 ft	Sun	Medium	Zone 3b
sand dropseed Sporobolus cryptandrus	Grass or grass-like	3 ft	Sun	Low	Zone 3b
Sandberg bluegrass Poa secunda	Grass or grass-like	1.4 ft	Sun–part shade	Low	Zone 3b
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
scabland penstemon Penstemon deustus	Wildflower (forb)	2 ft	Sun	Low	Zone 4a
scabland sagebrush Artemisia rigida	Shrub	2 ft	Sun	Low	Zone 3a
scarlet gilia Ipomopsis aggregata	Wildflower (forb)	3 ft	Sun	Low	Zone 5b
scarlet globemallow Sphaeralcea coccinea	Wildflower (forb)	1.5 ft	Sun	Low	Zone 5a
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
sharpleaf penstemon Penstemon acuminatus	Wildflower (forb)	2 ft	Sun	Low	Zone 4a
shortawn foxtail Alopecurus aequalis	Grass or grass-like	2.5 ft	Sun–part shade	High	Zone 3b
showy milkweed Asclepias speciosa	Wildflower (forb)	6 ft	Sun	Medium	Zone 4a
Sierra rush Juncus nevadensis	Grass or grass-like	2 ft	Sun–part shade	High	Zone 4a
silky lupine Lupinus sericeus	Wildflower (forb)	6 ft	Sun	Low	Zone 4b
silverleaf phacelia Phacelia hastata	Wildflower (forb)	2 ft	Sun–part shade	Medium	Zone 3b
silvery lupine Lupinus argenteus	Wildflower (forb)	1.5 ft	Sun	Low	Zone 3a
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
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
smallwing sedge Carex microptera	Grass or grass-like	2 ft	Sun	High	Zone 4a
smooth sumac Rhus glabra	Tree	12 ft	Sun	Low	Zone 4a
snowbrush ceanothus Ceanothus velutinus	Tree	10 ft	Sun	Medium	Zone 5a
spike trisetum Trisetum spicatum	Grass or grass-like	1.9 ft	Sun–part shade	Medium	Zone 3b
spineless horsebrush Tetradymia canescens	Shrub	4 ft	Sun	Low	Zone 9a
spiny hopsage Grayia spinosa	Shrub	3 ft	Sun	Low	Zone 4a
spreadingpod rockcress Arabis ×divaricarpa	Wildflower (forb)	3 ft	Shade-tolerant	Low	Zone 4b
squirreltail Elymus elymoides	Grass or grass-like	1.5 ft	Sun	Low	Zone 3a
sticky cinquefoil Potentilla glandulosa	Wildflower (forb)	1.5 ft	Sun–part shade	Low	Zone 4a
sulphur-flower buckwheat Eriogonum umbellatum	Shrub	1 ft	Sun	Low	Zone 8a
tailcup lupine Lupinus caudatus	Wildflower (forb)	5 ft	Sun	Low	Zone 4b
tall cottongrass Eriophorum angustifolium	Grass or grass-like	2 ft	Sun	High	Zone 3a
tall groundsel Senecio hydrophiloides	Wildflower (forb)	10 in	Shade-tolerant	High	Zone 4b
tall woolly buckwheat Eriogonum elatum	Wildflower (forb)	3 ft	Sun	Low	Zone 4b
tapertip hawksbeard Crepis acuminata	Wildflower (forb)	3 ft	Sun–part shade	Low	Zone 3b
tapertip onion Allium acuminatum	Wildflower (forb)	1 ft	Sun	Low	Zone 4b
tarweed fiddleneck Amsinckia lycopsoides	Wildflower (forb)	3 ft	Sun	Low	Zone 4b
teal lovegrass Eragrostis hypnoides	Grass or grass-like	4 in	Sun	High	Zone 3b
thickspike wheatgrass Elymus lanceolatus	Grass or grass-like	2.3 ft	Sun	Low	Zone 3b
thimbleberry Rubus parviflorus	Shrub	4 ft	Sun–part shade	High	Zone 4b
Thurber's needlegrass Achnatherum thurberianum	Grass or grass-like	2 ft	Sun	Low	Zone 5a
thymeleaf buckwheat Eriogonum thymoides	Wildflower (forb)	1 ft	Sun	Low	Zone 5a
Tolmie's onion Allium tolmiei	Wildflower (forb)	1 ft	Sun	Medium	Zone 4a
Torrey's rush Juncus torreyi	Grass or grass-like	3.1 ft	Sun	Medium	Zone 3b
tufted evening primrose Oenothera caespitosa	Wildflower (forb)	6 in	Sun	Low	Zone 6a
twinberry honeysuckle Lonicera involucrata	Shrub	10 ft	Shade-tolerant	High	Zone 3a
Utah honeysuckle Lonicera utahensis	Shrub	5 ft	Shade-tolerant	High	Zone 5a
Utah serviceberry Amelanchier utahensis	Tree	15 ft	Sun–part shade	Medium	Zone 4b
valdivia duckweed Lemna valdiviana	Wildflower (forb)	1 in	Sun	High	Zone 4a
water birch Betula occidentalis	Tree	25 ft	Sun–part shade	High	Zone 1a
water sedge Carex aquatilis	Grass or grass-like	2.9 ft	Sun	High	Zone 3b
wavyleaf Indian paintbrush Castilleja applegatei	Wildflower (forb)	1.5 ft	Sun	Low	Zone 4b
wax currant Ribes cereum	Shrub	3 ft	Sun	Low	Zone 5a
western juniper Juniperus occidentalis	Tree	33 ft	Sun	Low	Zone 4a
western stoneseed Lithospermum ruderale	Wildflower (forb)	1.5 ft	Sun	Low	Zone 4b
western sweetroot Osmorhiza occidentalis	Wildflower (forb)	4 ft	Shade-tolerant	Medium	Zone 3b
western white clematis Clematis ligusticifolia	Vine	1 ft	Sun–part shade	Medium	Zone 3b
white alder Alnus rhombifolia	Tree	65 ft	Shade-tolerant	High	Zone 5a
white fir Abies concolor	Tree	120 ft	Sun–part shade	Medium	Zone 3b
whitebark raspberry Rubus leucodermis	Vine	1 ft	Sun	Medium	Zone 8a
whitestem gooseberry Ribes inerme	Shrub	8 ft	Shade-tolerant	Medium	Zone 4b
Wilcox's penstemon Penstemon wilcoxii	Wildflower (forb)	3 ft	Sun	Low	Zone 4a
woolly groundsel Packera cana	Wildflower (forb)	1.5 ft	Sun	Low	Zone 3a
woollypod milkvetch Astragalus purshii	Wildflower (forb)	7 in	Sun	Low	Zone 4a
yellow fritillary Fritillaria pudica	Wildflower (forb)	1 ft	Sun–part shade	Medium	Zone 12a
yellow rabbitbrush Chrysothamnus viscidiflorus	Shrub	3 ft	Sun	Low	Zone 5a
yellow spiderflower Cleome lutea	Wildflower (forb)	2.7 ft	Sun	Low	Zone 12a
yellow wildrye Leymus flavescens	Grass or grass-like	3 ft	Sun	Medium	Zone 5b
yellow willow Salix lutea	Tree	16 ft	Sun–part shade	High	Zone 3a

Other native species recorded here 75

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.

American bird's-foot trefoil Lotus unifoliolatus
American mannagrass Glyceria grandis
arroyo willow Salix lasiolepis
bastard toadflax Comandra umbellata
bearded flatsedge Cyperus squarrosus
Bicknell's cranesbill Geranium bicknellii
big devils beggartick Bidens vulgata
bigseed alfalfa dodder Cuscuta indecora
bog yellowcress Rorippa palustris
Canadian gooseberry Ribes oxyacanthoides
carelessweed Cyclachaena xanthiifolia
clammy hedgehyssop Gratiola neglecta
clustered broomrape Orobanche fasciculata
Cuman ragweed Ambrosia psilostachya
curlycup gumweed Grindelia squarrosa
curlytop knotweed Polygonum lapathifolium
desert princesplume Stanleya pinnata
Douglas' knotweed Polygonum douglasii
Dudley's rush Juncus dudleyi
dutchman's breeches Dicentra cucullaria
feathery false lily of the valley Maianthemum racemosum
fireberry hawthorn Crataegus chrysocarpa
flatspine bur ragweed Ambrosia acanthicarpa
flatspine stickseed Lappula occidentalis
foxtail barley Hordeum jubatum
giant red Indian paintbrush Castilleja miniata
hairy evening primrose Oenothera villosa
hairy waterclover Marsilea vestita
hedge false bindweed Calystegia sepium
hoary tansyaster Machaeranthera canescens
hookedspur violet Viola adunca
Hornemann's willowherb Epilobium hornemannii
lanceleaf figwort Scrophularia lanceolata
largeleaf sandwort Moehringia macrophylla
lemon scurfpea Psoralidium lanceolatum
liverleaf wintergreen Pyrola asarifolia
manyflowered monkeyflower Mimulus floribundus
meadow deathcamas Zigadenus venenosus
meadow horsetail Equisetum pratense
Menzies' campion Silene menziesii
Menzies' fiddleneck Amsinckia menziesii
mountain tansymustard Descurainia incana
mountain tarweed Madia glomerata
muskflower Mimulus moschatus
narrowleaf goosefoot Chenopodium leptophyllum
narrowleaf minerslettuce Montia linearis
needleleaf navarretia Navarretia intertexta
northern water plantain Alisma triviale
northern watermeal Wolffia borealis
oneflowered broomrape Orobanche uniflora
Oregon cliff fern Woodsia oregana
pale spikerush Eleocharis macrostachya
pinyon goosefoot Chenopodium atrovirens
povertyweed Iva axillaris
purple reedgrass Calamagrostis purpurascens
roughfruit fairybells Prosartes trachycarpa
roundleaf sundew Drosera rotundifolia
shaggy fleabane Erigeron pumilus
slender phlox Microsteris gracilis
spearleaf stonecrop Sedum lanceolatum
spreading dogbane Apocynum androsaemifolium
starry false lily of the valley Maianthemum stellatum
sweetcicely Osmorhiza berteroi
tarragon Artemisia dracunculus
tiny trumpet Collomia linearis
tufted lovegrass Eragrostis pectinacea
turion duckweed Lemna turionifera
twinflower Linnaea borealis
veiny dock Rumex venosus
velvetweed Oenothera curtiflora
western tansymustard Descurainia pinnata
whitestem blazingstar Mentzelia albicaulis
wild cucumber Echinocystis lobata
witchgrass Panicum capillare
woolly sedge Carex pellita

Also listed as native and introduced here 3

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
Kentucky bluegrassPoa pratensis
white sagebrushArtemisia ludoviciana

Compared with Idaho

The typical county is the median of the 44 Idaho 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 Idaho
Measure	Washington County	Typical county	Statewide
Native species	267	302	975
Garden-ready natives	192	211	591
Tree	32	—	65
Shrub	28	—	97
Wildflower (forb)	154	—	552
Grass or grass-like	44	—	206
Vine	6	—	14
Fern	3	—	41

Neighboring counties

Counties that share a ZIP code with Washington County.

Adams County, ID 266 garden-ready
Payette County, ID 66 garden-ready

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 16087), Idaho. 267 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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