Quick answer: 66 native Oregon plants have a recorded bloom range that includes May.
66 species
- Alderleaf mountain mahogany Cercocarpus montanus · 15 states
- Antelope bitterbrush Purshia tridentata · 12 states
- Arrowleaf balsamroot Balsamorhiza sagittata · 12 states
- Baby blue eyes Nemophila menziesii · 3 states
- Bearberry Arctostaphylos uva-ursi · 34 states
- Bigleaf maple Acer macrophyllum · 3 states
- Bluebunch wheatgrass Pseudoroegneria spicata · 16 states
- Bog Labrador tea Ledum groenlandicum · 11 states
- Broadleaf cattail Typha latifolia · 39 states
- Bunchberry Cornus canadensis · 18 states
- California bay laurel Umbellularia californica · 3 states
- California flannelbush Fremontodendron californicum · 3 states
- California poppy Eschscholzia californica · 6 states
- Canada wild rye Elymus canadensis · 37 states
- Checker lily Fritillaria affinis · 3 states
- Chokecherry Prunus virginiana · 44 states
- Common camas Camassia quamash · 3 states
- Common yarrow Achillea millefolium · 47 states
- Creeping Oregon grape Mahonia repens · 15 states
- Crevice alumroot Heuchera micrantha · 4 states
- Deerbrush Ceanothus integerrimus · 5 states
- Douglas fir Pseudotsuga menziesii · 12 states
- Douglas iris Iris douglasiana · 3 states
- Globe gilia Gilia capitata · 5 states
- Greenleaf manzanita Arctostaphylos patula · 9 states
- Henderson's shooting star Dodecatheon hendersonii · 3 states
- Idaho fescue Festuca idahoensis · 12 states
- Indian ricegrass Achnatherum hymenoides · 17 states
- Lewis flax (blue flax) Linum lewisii · 17 states
- Lewis' mock orange Philadelphus lewisii · 5 states
- Marsh marigold Caltha palustris · 28 states
- Miniature lupine Lupinus bicolor · 4 states
- Mule's ears Wyethia amplexicaulis · 8 states
- Munro's globemallow Sphaeralcea munroana · 9 states
- Oceanspray Holodiscus discolor · 9 states
- Oregon white oak Quercus garryana · 3 states
- Pacific madrone Arbutus menziesii · 3 states
- Pacific trillium Trillium ovatum · 3 states
- Ponderosa pine Pinus ponderosa · 16 states
- Prairie Junegrass Koeleria macrantha · 29 states
- Purple sage (desert sage) Salvia dorrii · 7 states
- Quaking aspen Populus tremuloides · 39 states
- Red-flowering currant Ribes sanguineum · 4 states
- Red-osier dogwood Cornus sericea · 36 states
- Rocky Mountain bee plant Peritoma serrulata · 26 states
- Rocky Mountain iris Iris missouriensis · 11 states
- Royal penstemon Penstemon speciosus · 6 states
- Saskatoon serviceberry Amelanchier alnifolia · 14 states
- Scarlet monkeyflower Erythranthe cardinalis · 7 states
- Seaside daisy Erigeron glaucus · 2 states
- Seep monkeyflower Erythranthe guttata · 15 states
- Showy milkweed Asclepias speciosa · 17 states
- Silver buffaloberry Shepherdia argentea · 17 states
- Siskiyou lewisia Lewisia cotyledon · 2 states
- Smooth sumac Rhus glabra · 42 states
- Snowbrush ceanothus Ceanothus velutinus · 10 states
- Sticky monkeyflower Mimulus aurantiacus · 2 states
- Tall Oregon grape Mahonia aquifolium · 3 states
- Tufted evening primrose Oenothera caespitosa · 15 states
- Upland larkspur Delphinium nuttallianum · 13 states
- Vine maple Acer circinatum · 3 states
- Western azalea Rhododendron occidentale · 3 states
- Western blue-eyed grass Sisyrinchium bellum · 2 states
- Western yarrow Achillea millefolium var. occidentalis · 18 states
- Winterfat Krascheninnikovia lanata · 12 states
- Wyoming Indian paintbrush Castilleja linariifolia · 9 states
May in an Oregon native garden
May is Oregon's peak bloom month: 66 of the state's 88 native plants in this directory flower in May, more than in any other month.
23 start blooming in May, including Bluebunch wheatgrass, Bog Labrador tea and Bunchberry. 12 finish in May, including Alderleaf mountain mahogany, Bigleaf maple and Douglas fir, so this is the last chance to see them in flower.
53 of them grow in full or partial sun and 18 tolerate shade, so there are options for open beds and woodland edges alike. Sizes run from low plants like Arrowleaf balsamroot and Bluebunch wheatgrass to trees such as Alderleaf mountain mahogany and Bearberry. For wildlife, 45 support pollinators, 28 provide food or cover for birds and 8 are caterpillar host plants.
36 of the 66 have a seed or plant listing we verified as the wild species. Be careful buying Common yarrow: common listings for it are often a bred variety or a different species.
Good places to start
Verified wild-species listings that take sun and are widely native, so they are forgiving first plants.
- Chokecherry Prunus virginiana · Sun, Part Shade, Shade · blooms Apr-Jul
- Smooth sumac Rhus glabra · Sun, Part Shade, Shade · blooms May-Aug
- Quaking aspen Populus tremuloides · Sun, Part Shade, Shade · blooms Mar-Jun