Idaho Nature Guide: March 2026
March is the great turn in Idaho's lowlands. The Snake River Birds of Prey raptors return to their canyon cliffs in force, Greater Sage-Grouse begin their dawn dances on the high-desert leks, and snow geese and waterfowl pour through the Snake River Plain on their way north — one of the state's very best birding months.
What to look for this week
- Bald Eagles line the Snake River and the kokanee-rich Lake Coeur d'Alene, while Trumpeter Swans ride the ice-free, spring-fed water of Henry's Fork.
- The Quadrantid meteor shower peaks in a brief, sharp burst around January 3 — watch the dark northeast after midnight from the Snake River Plain or the Sawtooth valleys.
- In the warm Treasure Valley, dig the last mulched carrots and leeks on a thaw and finish dormant pruning of apples once the cold eases.
- Ponderosa pine and Douglas-fir carry the snowy mountains in dark green while the bare western larch stands gray across the north-Idaho forests.
Birds This Month
March is one of Idaho's premier birding months. The Snake River Birds of Prey National Conservation Area south of Boise comes alive as Prairie Falcons, Golden Eagles, Red-tailed and Ferruginous Hawks, and Northern Harriers set up on the canyon cliffs — the densest concentration of nesting raptors in North America, with the falcons keyed to the spring emergence of ground squirrels. On the high-desert leks of the sagebrush steppe, Greater Sage-Grouse begin their famous strutting displays at dawn, and Sharp-tailed Grouse dance on their own grounds.
Waterfowl migration peaks: Snow Geese, Ross's Geese, Tundra Swans, and clouds of Northern Pintail, American Wigeon, and Green-winged Teal stage on the Snake River Plain wetlands and the Camas and Deer Flat refuges. Sandhill Cranes return to the eastern Idaho valleys, Mountain Bluebirds — the state bird — flash blue along the foothill fences, and Say's Phoebes and Tree Swallows arrive.
What's Blooming
March opens the Idaho wildflower year on the warm, low slopes. Sagebrush buttercup spreads its glossy yellow across south-facing foothill and canyon ground in the Treasure Valley and the lower Snake and Salmon country, soon joined by the white-and-pink spring beauty (Claytonia), the yellow bells of Fritillaria pudica, and the first grass widows and shooting stars in the moister draws. The Boise Front foothills begin to green and freckle with these earliest blooms.
The canyon grasslands of the lower Clearwater, Salmon, and Snake rivers — Idaho's mildest microclimates — lead the show, with yellow bells, buttercups, and the first arrowleaf balsamroot leaves pushing up. Higher up, the mountains and the Camas Prairie are still snowbound and weeks from bloom. Along the rivers, the catkins of willow, alder, and black cottonwood open and dust the air with the first tree pollen of the year.
Garden This Month
March opens the outdoor garden in Idaho's warmer valleys while the high country waits. In the Treasure Valley and the southwestern fruit country, the soil dries enough to direct-sow peas, spinach, radishes, lettuce, carrots, and beets, and to plant onion sets, seed potatoes, and bare-root asparagus, rhubarb, and fruit trees by mid-to-late month. Cool-season transplants — broccoli, cabbage, and kale — can go out under protection toward the end of March.
Indoors, the seed-starting accelerates: sow tomatoes, peppers, and eggplant under lights now so they're ready for the warm-season transplant date in May. Watch the clear-night frosts, which run hard and late across the whole state, and keep row cover ready for sudden cold. In the eastern Snake River Plain and the mountain valleys, the ground is still frozen and the work stays indoors — Idaho's short, frost-bracketed high-valley season won't truly open for two more months.
Zone 4b (eastern Snake River Plain & mountain valleys): still mostly frozen. Keep starting seedlings indoors and prepping beds as they thaw, but outdoor sowing waits — the frost-free window here doesn't open until late May or June.
Zone 5b (Boise foothills & Magic Valley): sow peas, spinach, and radishes as soon as the soil dries enough to work, and start tomatoes and peppers indoors. Hold tender crops — hard frosts still come, so keep row cover handy.
Zone 6a (warmest Treasure Valley & lower Snake River): the outdoor season opens. Direct-sow peas, spinach, radishes, lettuce, and carrots, plant onion sets and seed potatoes mid-to-late month, and set out cool-season brassica transplants. Plant bare-root fruit trees and asparagus.
What's at the Farmers Market
March markets in Idaho are still in their lean late-winter phase, carried by storage crops and the first greenhouse greens. The Idaho potato remains the centerpiece — russets, reds, golds, and fingerlings still firm from cold storage — alongside storage Treasure Valley onions, carrots, beets, parsnips, cabbage, and winter squash, and dried Palouse lentils, split peas, and chickpeas from the northern Idaho hills.
The first fresh growth of the year appears from hoop houses and heated greenhouses around Boise and Twin Falls: tender spinach, lettuce, arugula, radishes, and green onions, plus the very first cuttings of overwintered chives and herbs. Idaho's value-added goods round out the stand — honey, dried beans and grains, hard cider, wine, and fresh-milled flour. Choose firm, unsprouted potatoes and store them cool and dark, pick crisp, bright greens and refrigerate them promptly, and keep dried legumes airtight in a cool pantry where they hold for a year or more.
Night Sky This Month
March balances long, dark nights with milder temperatures, opening Idaho's dark-sky country to more comfortable viewing. The Central Idaho Dark Sky Reserve around the Sawtooths, Stanley, and Sun Valley remains the premier destination — the first International Dark Sky Reserve in the U.S. — while Bruneau Dunes State Park resumes its spring observatory programs and the wide Snake River Plain and high Lost River country offer transparent skies for Treasure Valley and eastern-Idaho observers alike.
The sky is in transition: Orion and the Winter Hexagon sink into the west after dark while Leo climbs in the east and the Big Dipper rides high overhead, its handle arcing to Arcturus rising in the late evening. The spring equinox near March 20 evens the day and night. No major meteor shower peaks this month. For this year's exact planet positions and the latest aurora outlook, see the printable Idaho night-sky guide.
Butterflies & Pollinators
March brings the first real butterfly activity to Idaho's lower valleys. On warm, sunny afternoons in the Treasure Valley and the lower Snake, Boise, and Clearwater river country, overwintered Mourning Cloaks patrol the riverside woods, joined by waking Milbert's and California Tortoiseshells and the small, fast anglewings (Satyr and Green Commas), all of them hibernating adults taking advantage of the strengthening sun before any new generation hatches.
By late month, the season's first freshly emerged butterflies appear on the warm foothill slopes: the Sara Orangetip, flashing bright orange wingtips along the canyon grasslands as it tracks the earliest mustards, and early spring whites and azures. The Anise Swallowtail may begin hilltopping on the warmest lava-country ridges. The mountains and the Camas Prairie remain snowbound, their butterflies still weeks from flight, so all the action is low and sun-warmed.
Trees This Month
March stirs Idaho's lowland trees into spring while the mountains hold winter. Along the Snake River Plain and the southwestern valleys, the black cottonwood, willow, water birch, and aspen hang out fresh catkins and break their first buds, and the riverside quaking aspen groves begin to leaf in the warmest draws. The native chokecherry, serviceberry, and Rocky Mountain maple swell toward bloom, and in town the early ornamental plums and maples flower.
The conifer forests stand unchanged in dark green across the mountains — ponderosa pine on the canyon slopes, Douglas-fir and grand fir on the heights, and the great western white pine, western redcedar, and western hemlock of the north-Idaho panhandle. The bare, gray western larch waits among them for its spring needle flush. On the dry slopes, Rocky Mountain juniper and the silver of sagebrush carry their evergreen color as the snowline begins to climb the foothills.
Go deeper with the Idaho guides
The complete Idaho birding, native-plant, wildflower, and night-sky guides — or the whole year in one bundle.
Same month elsewhere: March in Illinois · March in Indiana · March in Iowa