Iowa Nature Guide: March 2026
March is migration month in Iowa — one of the great natural events of the state's year. Hundreds of thousands of snow geese sweep up the Missouri flyway, sandhill cranes pass overhead, and the first spring ephemerals push through thawing woodland soil. Winter loosens its grip, though late snow is still likely.
What to look for this week
- Feeders are at their winter peak — chickadees, nuthatches, and cardinals work the seed, while wintering bald eagles already crowd the open water below the Mississippi dams at Keokuk and Le Claire.
- The Quadrantid meteor shower peaks in a short, sharp burst around January 3; watch the northeast after midnight from a dark site like the Loess Hills ridges.
- A planning week — order seeds early and favor the short-season varieties that finish reliably in northern Iowa's cold.
Birds This Month
March is the peak of spring migration in Iowa and one of the best birding months of the year. The snow goose migration up the Missouri flyway reaches its crescendo, with staggering flocks — sometimes hundreds of thousands of birds — staging in flooded fields and wetlands at Riverton, Forney Lake, and along the western river bottoms, mixed with greater white-fronted geese and Ross's geese. Sandhill cranes pass overhead in bugling skeins, and waterfowl of every kind — northern pintail, green-winged teal, canvasback, and more — crowd the marshes.
Closer to home, the first migrants trickle in: red-winged blackbirds claiming cattail marshes, common grackles and killdeer returning, American robins arriving in flocks, and the first turkey vultures tilting over the timber. American white pelicans begin appearing on the rivers and reservoirs late in the month.
This month's tip: dawn at a western Iowa wetland during the snow goose peak is unforgettable — the roar and the white tornado of birds lifting off the water is a signature Iowa wildlife spectacle worth the early drive.
What's Blooming
March brings Iowa's first true blooms as the soil thaws. The earliest is silver maple, its red flowers opening on bare branches in the bottomlands before any other tree. On the woodland floor, the very first spring ephemerals emerge in the southern and eastern counties: snow trillium, a tiny early native, and the unusual skunk cabbage in cold seeps, which can generate its own heat to melt surrounding snow. In gardens and lawns, snowdrops and the first crocuses push up in sheltered south-facing spots, and pussy willows finish opening their silver catkins along the streams. By the end of the month, on the dry hill prairies of the Loess Hills, the lavender cups of pasque flower — one of Iowa's most beloved prairie wildflowers — begin to open on warm, sunny slopes.
Garden This Month
March is when the Iowa garden finally moves outdoors, though patiently. As the frost leaves the ground and the top few inches dry enough to crumble rather than smear, direct-sow the cold-hardy crops: peas, spinach, lettuce, radishes, and onion sets all tolerate the cold nights and even light snow. This is also the prime window to plant bare-root fruit trees, asparagus crowns, and rhubarb, and to finish dormant pruning before buds break.
Indoors, start tomatoes, peppers, and eggplant under lights around mid-month so they are stocky transplants by the time the frost-free date arrives in May. Gradually pull back winter mulch from perennials and the strawberry bed as growth resumes, but keep some handy — a late-March snow or hard freeze is all but guaranteed, and tender new shoots will need re-covering on the coldest nights.
Zone 4b (far north Iowa): still mostly frozen — keep seedlings going indoors and wait. Late in the month, on a thawed day, you can prune dormant fruit trees and cut back last year's ornamental grasses and perennial stems before new growth begins.
Zone 5a (central Iowa): as soil dries enough to crumble, direct-sow the hardiest crops — peas, spinach, radishes, and lettuce — into prepared beds. Start tomatoes and peppers indoors under lights around mid-month for May transplanting.
Zone 5b (southern Iowa): the south warms first; sow peas, spinach, kale, and onion sets early in the month, plant bare-root trees and asparagus crowns, and uncover strawberries as growth resumes.
What's at the Farmers Market
The very first fresh local product of the Iowa year appears in March: maple syrup. Sugar maples in the eastern bluff country and the southeast run hard during the freeze-thaw days of early spring, and producers boil down the new season's syrup, which arrives at winter markets in amber jars. This is the season's signature taste.
Storage crops still anchor the markets — onions, potatoes, carrots, beets, and winter squash from the cellar — though stored apples are nearly finished. The first cold-hardy fresh greens from hoop houses begin to come on stronger now: spinach, mâche, kale, and the earliest cutting lettuces, along with eggs as hens resume heavier laying with the lengthening days. Look for honey from last year's hives as well. Choose firm, heavy roots, and store the season's last squash somewhere cool and dry.
Night Sky This Month
March is a transitional sky over Iowa, balanced between the brilliant winter stars and the rising spring constellations. In the early evening, Orion and the Winter Hexagon still command the southwest, but they sink earlier each night. Climbing in the east is Leo the Lion, its backward-question-mark 'Sickle' marking the head and bright Regulus at its base — the herald of spring skies. The Big Dipper swings high overhead, its pointer stars aiming down to Polaris and the North Star.
The spring equinox around March 20 evens out day and night, and from then on Iowa's evenings lengthen quickly. Late in the month, the zodiacal light — a faint pyramid of sunlight scattered by interplanetary dust — can be glimpsed in the western sky after full dark from a truly dark site like the Loess Hills ridgetops.
Exact planet positions change year to year — the printable Iowa night-sky guide lists what's visible this month from your part of the state.
Butterflies & Pollinators
March marks the awakening of Iowa's butterfly season on its first warm, sunny days. The overwintering adults emerge first: mourning cloaks are the classic early flier, gliding along sunlit woodland edges and over still-brown prairie, sometimes while patches of snow remain. They are joined by eastern commas and question marks, two angle-winged species that also overwinter as adults and bask on tree trunks and warm leaf litter. Compton tortoiseshells may appear in the northeast. These early butterflies feed not on flowers — there are few yet — but on tree sap, especially at the cuts and breaks where maple sap is running. The migratory monarchs are still far to the south, just beginning to move north out of Mexico into Texas, generations away from reaching Iowa. A March butterfly sighting is one of the surest signs that the long winter is finally breaking.
Trees This Month
March is when Iowa's trees break dormancy from the ground up. The bottomland silver maples and red maples flower first, their red blossoms a faint flush against the gray timber before any leaves appear. Eastern cottonwoods along the rivers begin pushing out their reddish catkins, and the American elms that survive scatter tiny flowers high in their crowns. The pussy willows are in full silver display along the streams.
This is also the close of the maple-sap season; in the eastern bluff country and southeast, the freeze-thaw run that has fed the syrup boil tapers off as the trees' buds begin to swell. The oaks, hickories, and walnuts remain bare and cautious — Iowa's late-leafing trees that wait out the threat of frost — but their buds are visibly fattening, and the first faint green haze of the year is only weeks away.
Go deeper with the Iowa guides
The complete Iowa birding, native-plant, wildflower, and night-sky guides — or the whole year in one bundle.
Same month elsewhere: March in Kansas · March in Kentucky · March in Louisiana