Illinois Nature Guide: March 2026
March is the great thaw in Illinois — the rivers swell, the prairie greens at its base, and migration surges. Sandhill cranes stream north overhead, the first spring ephemerals open on the forest floor, and waterfowl crowd the river backwaters in some of the year's biggest numbers.
What to look for this week
- Bald eagles concentrate at the open water below the Mississippi and Illinois river dams, fishing the churning tailwaters in the season's classic Illinois winter spectacle.
- The Quadrantid meteor shower peaks in a short, sharp burst around January 3 — watch the northeast after midnight from a dark site away from city lights.
- A planning week: order seeds early, and leave any snow banked over perennial beds as the best insulation an Illinois garden gets.
Birds This Month
March is one of the most dynamic birding months of the Illinois year. The headline is the sandhill crane migration — long, wavering lines of bugling cranes stream north over the eastern half of the state, many having staged at the famous Jasper-Pulaski marsh just over the Indiana line. Waterfowl numbers peak as the ice goes out: northern pintail, green-winged teal, northern shoveler, gadwall, wood ducks, and thousands of snow and greater white-fronted geese crowd Emiquon, the Illinois River backwaters, and flooded fields.
On land, the first migrant songbirds arrive — red-winged blackbirds claim the marshes with their 'conk-la-ree,' eastern meadowlarks sing from fence posts, American woodcock begin their spiraling twilight display flights over wet thickets, and the first eastern phoebes and tree swallows appear by month's end. American robins flood the lawns and turkey vultures return to ride the warming thermals. It's a fine month to set up nest boxes before the bluebirds and tree swallows compete for them.
What's Blooming
March is when the Illinois woodland floor comes alive with the first spring ephemerals — the brief, beautiful flowers that bloom before the canopy leafs out and steals the light. Bloodroot opens its single white flower over a clasping leaf, the diminutive harbinger-of-spring (one of the earliest) scatters across rich woods, and spring beauty, cutleaf toothwort, hepatica, and the nodding yellow trout lily follow in the warmer south first, then northward. In wet woods and floodplains, marsh marigold begins to glow gold. Look in the rich river-bottom forests along the Illinois and Mississippi for the first emerging leaves of Virginia bluebells, which will carpet the floodplain blue in April. In gardens, crocus, snowdrops, winter aconite, and the first daffodils open as the soil warms.
Garden This Month
March is when Illinois gardens finally come back to life. Once the soil has dried enough to crumble rather than smear, direct-sow the cool-season crops that thrive in cold ground: peas, spinach, lettuce, radishes, carrots, beets, and potatoes, and set out onion sets and transplants. Indoors, keep tomatoes, peppers, and eggplant growing under lights for a May transplant.
This is the month to cut back last year's perennials and ornamental grasses, but wait until temperatures are reliably above the 50s for a stretch so overwintering pollinators in the hollow stems can emerge. Prune roses and summer-blooming shrubs as buds swell, finish dormant fruit-tree pruning, and top-dress beds with compost. Don't rush warm-season planting — the last frost is still six to eight weeks off in the north — and don't work soil that's still soggy from the thaw.
Zone 5b (Chicago metro & northern Illinois): as soil dries, direct-sow the hardiest crops — peas, spinach, radishes, and lettuce — and set out onion sets; keep tomato and pepper seedlings going strong under lights for a May transplant.
Zone 6a (central Illinois): the soil works earlier here — plant peas, potatoes, onions, and cool-season greens mid-month, and prune roses and summer-flowering shrubs as growth resumes.
Zone 7a (far southern Illinois / 'Little Egypt'): the state's earliest gardens are running — plant a full cool-season garden of peas, lettuce, brassicas, carrots, and potatoes, and harden off transplants for an early set-out.
What's at the Farmers Market
March markets sit between winter storage and the first spring harvest. Indoor and early-opening markets still carry the last of the storage crops — onions, potatoes, carrots, cabbage, and a dwindling supply of winter squash and cold-stored apples — but the season's first fresh greens from hoop houses begin to appear: spinach, arugula, lettuce, and early radishes.
The signature March product is maple syrup: this is peak sap-run season across Illinois, and fresh syrup from the spring boil shows up at markets and farm stands, often graded from light early-run to darker late-run. Look also for honey, eggs, and microgreens. Choose the firmest, freshest greens and use them within a few days; keep any remaining storage roots cool, dark, and humid. The energy of the markets builds noticeably as the first true spring crops near.
Night Sky This Month
March brings the spring equinox around the 20th, when day and night reach near-equal length and the sun crosses the celestial equator. The evening sky is in transition: brilliant Orion and the Winter Hexagon still dominate the southwest after dark but sink earlier each night, while Leo the Lion, with the bright star Regulus, climbs in the east to mark the coming of spring's constellations. The Big Dipper swings high overhead.
There's no major meteor shower in March, so it's a month for the bright stars and, with a telescope, the galaxies of the spring sky beginning to rise. The dark skies of the Shawnee National Forest in far southern Illinois remain the state's best escape from the Chicago metro's light dome.
The printable Illinois night-sky guide lists this year's planet positions and the exact equinox timing for your location.
Butterflies & Pollinators
March brings the first butterflies of the Illinois year. On the first genuinely warm, sunny days — earlier in the south, later north — the overwintering adults wake and fly: mourning cloaks with their cream-edged dark wings, eastern commas, and question marks patrol sunny woodland edges and clearings, often over ground still patched with snow. These are last summer's butterflies, worn and faded after a long winter, taking advantage of the first warmth to feed on sap and bask. The tiny spring azure, a delicate powder-blue, is often the first fresh butterfly to emerge from its chrysalis later in the month. The state's monarchs are now moving north through Texas and the southern plains, still weeks from reaching Illinois. Establish native milkweed now so it's growing when the first monarchs arrive in May.
Trees This Month
March is the start of Illinois's tree-flowering season, which runs from the bottom up and the south north. The silver and red maples bloom first, their reddish flower clusters tinting whole hillsides before any leaves appear, while maple sugaring continues until the buds break. Cottonwoods and willows along the rivers push out catkins, and willow twigs turn yellow-green as their sap rises.
Later in the month, the lacy white flowers of serviceberry (Juneberry) and the magenta buds of native eastern redbud begin to color the woodland edges, especially in the warmer south where redbud and the white flowering dogwood are signature spring sights of the Shawnee hills. The oaks and hickories remain bare — they leaf out last — and the bald cypress of the southern swamps are still leafless, their feathery new needles a couple of months away.
Go deeper with the Illinois guides
The complete Illinois birding, native-plant, wildflower, and night-sky guides — or the whole year in one bundle.
Same month elsewhere: March in Indiana · March in Iowa · March in Kansas