New Jersey Nature Guide: September 2026
September is New Jersey's great migration month, when Cape May becomes one of the world's premier fall-migration sites — hawks, songbirds, and monarchs funnel down the peninsula and stage before crossing Delaware Bay. The air cools, goldenrod and asters peak, and the harvest rolls on.
What to look for this week
- Feeders are at their winter peak — chickadees, titmice, nuthatches, and cardinals work the seed, with dark-eyed juncos foraging beneath as the year's hardiest residents settle in.
- The Quadrantid meteor shower peaks in a short, sharp burst around January 3; watch the northeast after midnight from a dark Pine Barrens or shore site.
- A planning week at the kitchen table — order seeds, sketch next year's beds, and leave any snow banked over perennials as insulation against the cold.
Birds This Month
September is the climax of fall migration in New Jersey, and Cape May is its epicenter — one of the great migration spectacles on Earth. Northwest winds behind a cold front pile migrants onto the peninsula: clouds of warblers, vireos, flycatchers, thrushes, tanagers, and sparrows drip from the bayside woods at dawn, while the famous hawk watch at Cape May Point tallies thousands of American kestrels, sharp-shinned and Cooper's hawks, merlins, ospreys, broad-winged hawks, and peregrine falcons streaming past.
The whole coast is alive. Shorebird migration continues at Forsythe (Brigantine) and the bays, Tree swallows mass in swirling clouds of hundreds of thousands over the dunes, and the bayshore concentrates songbirds, nighthawks, and monarchs. Inland, mixed flocks move through the Highlands and Pine Barrens, and the broad-winged hawk kettles peak mid-month.
This month's tip: visit Cape May the morning after a strong cold front with northwest winds — the dawn songbird flight and the daytime hawk watch on the same day can be the birding experience of a lifetime.
What's Blooming
September is the peak of New Jersey's gold-and-purple fall meadows. Goldenrods of many species blaze along every roadside and field — and contrary to their reputation, they don't cause hay fever; the wind-pollinated ragweed blooming at the same time is the true culprit. They're joined by a spectacular show of asters: deep-purple New England aster, sky-blue smooth and heath asters, and white panicled aster, the most important late nectar for migrating monarchs.
The wet meadows still hold Joe-Pye weed, boneset, turtlehead, cardinal flower, and great blue lobelia, and the Pine Barrens reach a late-season highlight as the deep-blue pine barren gentian opens in the damp savannas among the last goldenrod. Along the coast, seaside goldenrod lights up the dunes — a critical nectar source for the staging monarchs at Cape May — and the salt marshes flush bronze and gold with turning cordgrass.
Garden This Month
September is the great transition in the New Jersey garden, from harvest to fall. The fall crops sown in August — spinach, lettuce, kale, turnips, radishes, and the last beans — are sizing up, while tomatoes, peppers, and squash give their final flush before cool nights slow them. In the Highlands, watch for the first frost late in the month and harvest or cover tender crops ahead of it; in the south, there's still ample warm time.
This is the month to plant garlic (it overwinters for a summer harvest), to divide and replant overgrown perennials, peonies, and spring bulbs, and to plant trees and shrubs while the soil is warm and the rains return — fall is the ideal planting season here. As beds empty, sow cover crops like winter rye or clover to protect and build the soil. Clean up diseased plant debris, but leave seed heads and standing stems for the birds and overwintering insects.
Zone 6a (northwestern Highlands): first frost can arrive by late month, so harvest tender crops before it and cover or pick tomatoes ahead of the first cold night. Plant garlic, divide perennials, and sow cover crops as beds clear.
Zone 7a (central & southern New Jersey): the fall garden of greens and roots is producing, and frost is still weeks off — keep harvesting, plant garlic late in the month, and sow cover crops and a final round of fast greens.
Zone 7b (southern shore & Cape May): the long season continues well past month's end — keep harvesting summer and fall crops, sow more greens, and begin garlic and cover-crop planting in the still-warm soil.
What's at the Farmers Market
September markets in New Jersey bridge summer and fall, still abundant but shifting. The last Jersey tomatoes, sweet corn, peaches, melons, eggplant, and peppers of summer overlap with the arriving fall crops. Apples come on strong from the orchards, the first winter squash and pumpkins appear, and pears, broccoli, cauliflower, cabbage, greens, beets, and carrots fill the stands.
The first pressing of fresh apple cider arrives, and grapes and the last raspberries appear from some farms. Choose apples that are firm and heavy; pick winter squash with a hard, dull rind and a dry, corky stem and cure it in a warm, dry spot for storage; choose firm broccoli and cauliflower with tight heads. Store the last tomatoes at room temperature and use the final corn quickly. The markets are at their richest crossover, the summer and autumn harvests overlapping on the tables.
Night Sky This Month
September brings the autumn equinox around September 22, balancing day and night and ushering in the longer nights of fall. After dark the Summer Triangle still rides high overhead, but the autumn constellations are rising in the east: the Great Square of Pegasus, the chained figure of Andromeda, and the W-shaped Cassiopeia. From a dark site, the Andromeda Galaxy — 2.5 million light-years away and the most distant object visible to the unaided eye — is an easy binocular smudge near Andromeda's stars.
The Milky Way still arches overhead from the Summer Triangle down to Sagittarius setting in the southwest. There's no major meteor shower this month, so September is for steady deep-sky viewing as the nights lengthen and cool — the Double Cluster in Perseus rises high in the northeast, a glorious binocular sight.
The cooler, drier air sharpens the view from the Pine Barrens and the southern shore. Exact planet positions vary year to year — the printable New Jersey night-sky guide gives this year's details for your region.
Butterflies & Pollinators
September is the month of the monarch migration in New Jersey, one of the state's signature natural events. The final summer generation, born to migrate, streams southward and funnels down the Cape May peninsula, where on a good day after a cold front thousands stage in the dunes and roost in the cedars, fueling on seaside goldenrod and asters before crossing Delaware Bay on the long journey to central Mexico. The Cape May monarch count documents the spectacle each fall. Other butterflies remain active in the warm days — common buckeyes, painted and American ladies, red admirals, sulphurs, fiery and other late skippers, and the last swallowtails — all working the goldenrod and aster bloom. Planting late-blooming natives and leaving the goldenrod standing directly supports the migrating monarchs. Watch the coast on northwest winds for the river of orange wings.
Trees This Month
September begins New Jersey's slow turn to fall color. The earliest and most reliable turners lead: black gum (tupelo) flames a brilliant scarlet in the wet woods, red maple flushes red in the swamps, sassafras turns orange and red, sumac blazes crimson along the roadsides, and the flowering dogwood reddens its leaves around clusters of scarlet berries that fuel migrating birds. Black walnut and ash begin to yellow and drop early.
The mast crop is ripe and falling — acorns from the oaks, hickory nuts, beechnuts, and walnuts rain down, a feast for jays, squirrels, deer, and turkeys, and the jays are busy caching them. In the Pine Barrens, the evergreen pitch pine and Atlantic white cedar hold their green as the scattered hardwoods turn. The full blaze of October is still building, but the first torches of red and gold are lit across the state.
Go deeper with the New Jersey guides
The complete New Jersey birding, native-plant, wildflower, and night-sky guides — or the whole year in one bundle.
Same month elsewhere: September in New Mexico · September in New York · September in North Carolina