Quick answer: 47 native Montana plants have a recorded bloom range that includes May.
47 species
- Alderleaf mountain mahogany Cercocarpus montanus · 15 states
- American plum Prunus americana · 37 states
- Antelope bitterbrush Purshia tridentata · 12 states
- Arrowleaf balsamroot Balsamorhiza sagittata · 12 states
- Bearberry Arctostaphylos uva-ursi · 34 states
- Bluebunch wheatgrass Pseudoroegneria spicata · 16 states
- Broadleaf cattail Typha latifolia · 39 states
- Buffalograss Bouteloua dactyloides · 19 states
- Canada anemone Anemone canadensis · 29 states
- Canada wild rye Elymus canadensis · 37 states
- Chokecherry Prunus virginiana · 44 states
- Common hackberry Celtis occidentalis · 33 states
- Common yarrow Achillea millefolium · 47 states
- Creeping Oregon grape Mahonia repens · 15 states
- Creeping juniper Juniperus horizontalis · 12 states
- Douglas fir Pseudotsuga menziesii · 12 states
- Gray alder Alnus incana · 26 states
- Green ash Fraxinus pennsylvanica · 43 states
- Greenleaf manzanita Arctostaphylos patula · 9 states
- Highbush cranberry Viburnum opulus var. americanum · 22 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
- Mexican hat Ratibida columnifera · 17 states
- Mule's ears Wyethia amplexicaulis · 8 states
- Munro's globemallow Sphaeralcea munroana · 9 states
- Oceanspray Holodiscus discolor · 9 states
- Plains coreopsis Coreopsis tinctoria · 16 states
- Ponderosa pine Pinus ponderosa · 16 states
- Prairie Junegrass Koeleria macrantha · 29 states
- Quaking aspen Populus tremuloides · 39 states
- Red baneberry Actaea rubra · 29 states
- Red-osier dogwood Cornus sericea · 36 states
- Riverbank grape Vitis riparia · 20 states
- Rocky Mountain bee plant Peritoma serrulata · 26 states
- Saskatoon serviceberry Amelanchier alnifolia · 14 states
- Scarlet globemallow Sphaeralcea coccinea · 12 states
- Seep monkeyflower Erythranthe guttata · 15 states
- Showy milkweed Asclepias speciosa · 17 states
- Silver buffaloberry Shepherdia argentea · 17 states
- Smooth sumac Rhus glabra · 42 states
- Snowbrush ceanothus Ceanothus velutinus · 10 states
- Tufted evening primrose Oenothera caespitosa · 15 states
- Upland larkspur Delphinium nuttallianum · 13 states
- Wasatch penstemon Penstemon cyananthus · 4 states
- Western yarrow Achillea millefolium var. occidentalis · 18 states
May in a Montana native garden
May is one of Montana's busiest bloom months, with 47 of the state's 78 native plants flowering (the peak is June).
18 start blooming in May, including Bluebunch wheatgrass, Highbush cranberry and Idaho fescue. 6 finish in May, including Alderleaf mountain mahogany, Common hackberry and Creeping juniper, so this is the last chance to see them in flower.
43 of them grow in full or partial sun and 14 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 American plum. For wildlife, 33 support pollinators, 26 provide food or cover for birds and 11 are caterpillar host plants.
34 of the 47 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
- Green ash Fraxinus pennsylvanica · Sun, Part Shade, Shade · blooms Apr-Jun
- Smooth sumac Rhus glabra · Sun, Part Shade, Shade · blooms May-Aug