60 wildflowers were recorded blooming in Minnesota in September in our iNaturalist sample; 11 of the top 50 are at their peak this month. The list is ranked by number of research-grade observations.
Top wildflowers in September

Large-Leaved Aster

White Snakeroot

New England aster

Common Jewelweed

Broad-Leaved Goldenrod

Nodding Beggarticks

Common Toadflax

False Sunflower

Giant Ragweed

Great Blue Lobelia

brown-eyed Susan

Pearly Everlasting
All wildflowers blooming in Minnesota in September
| # | Species | Scientific name | Family | Obs. | Peak in state |
|---|---|---|---|---|---|
| 1 | Large-Leaved Aster | Eurybia macrophylla | Sunflowers, Daisies, Asters, and Allies | 308 | Aug (past peak) |
| 2 | White Snakeroot | Ageratina altissima | Sunflowers, Daisies, Asters, and Allies | 307 | Sep (peak) |
| 3 | New England aster | Symphyotrichum novae-angliae | Sunflowers, Daisies, Asters, and Allies | 275 | Sep (peak) |
| 4 | Common Jewelweed | Impatiens capensis | balsam family | 196 | Aug (past peak) |
| 5 | Broad-Leaved Goldenrod | Solidago flexicaulis | Sunflowers, Daisies, Asters, and Allies | 142 | Sep (peak) |
| 6 | Nodding Beggarticks | Bidens cernua | Sunflowers, Daisies, Asters, and Allies | 81 | Sep (peak) |
| 7 | Common Toadflax | Linaria vulgaris | Plantain Family | 79 | Sep (peak) |
| 8 | False Sunflower | Heliopsis helianthoides | Sunflowers, Daisies, Asters, and Allies | 74 | Jul (past peak) |
| 9 | Giant Ragweed | Ambrosia trifida | Sunflowers, Daisies, Asters, and Allies | 73 | Aug (past peak) |
| 10 | Great Blue Lobelia | Lobelia siphilitica | bellflower family | 73 | Aug (past peak) |
| 11 | brown-eyed Susan | Rudbeckia triloba | Sunflowers, Daisies, Asters, and Allies | 73 | Sep (peak) |
| 12 | Pearly Everlasting | Anaphalis margaritacea | Sunflowers, Daisies, Asters, and Allies | 66 | Aug (past peak) |
| 13 | Ghost Pipe | Monotropa uniflora | heath family | 64 | Aug (past peak) |
| 14 | Common Sneezeweed | Helenium autumnale | Sunflowers, Daisies, Asters, and Allies | 58 | Sep (peak) |
| 15 | spotted Joe-Pye weed | Eutrochium maculatum | Sunflowers, Daisies, Asters, and Allies | 58 | Aug (past peak) |
| 16 | black-eyed Susan | Rudbeckia hirta | Sunflowers, Daisies, Asters, and Allies | 57 | Jul (past peak) |
| 17 | Purple Loosestrife | Lythrum salicaria | lythrum family | 56 | Aug (past peak) |
| 18 | Flat-Top White Aster | Doellingeria umbellata | Sunflowers, Daisies, Asters, and Allies | 54 | Aug (past peak) |
| 19 | Red Clover | Trifolium pratense | Legumes | 52 | Jun (past peak) |
| 20 | Common Tansy | Tanacetum vulgare | Sunflowers, Daisies, Asters, and Allies | 51 | Aug (past peak) |
| 21 | Field Thistle | Cirsium discolor | Sunflowers, Daisies, Asters, and Allies | 49 | Aug (past peak) |
| 22 | Pale Jewelweed | Impatiens pallida | balsam family | 47 | Aug (past peak) |
| 23 | Fireweed | Chamaenerion angustifolium | evening primrose family | 41 | Aug (past peak) |
| 24 | Common Boneset | Eupatorium perfoliatum | Sunflowers, Daisies, Asters, and Allies | 40 | Aug (past peak) |
| 25 | Cutleaf Coneflower | Rudbeckia laciniata | Sunflowers, Daisies, Asters, and Allies | 38 | Aug (past peak) |
| 26 | Cardinal Flower | Lobelia cardinalis | bellflower family | 37 | Aug (past peak) |
| 27 | White Turtlehead | Chelone glabra | Plantain Family | 37 | Aug (past peak) |
| 28 | Sweet Everlasting | Pseudognaphalium obtusifolium | Sunflowers, Daisies, Asters, and Allies | 36 | Sep (peak) |
| 29 | Orange Hawkweed | Pilosella aurantiaca | Sunflowers, Daisies, Asters, and Allies | 34 | Jun (past peak) |
| 30 | Pinkweed | Persicaria pensylvanica | knotweed family | 33 | Aug (past peak) |
| 31 | White Campion | Silene latifolia | pink family | 33 | Jun (past peak) |
| 32 | American groundnut | Apios americana | Legumes | 33 | Aug (past peak) |
| 33 | American burnweed | Erechtites hieraciifolius | Sunflowers, Daisies, Asters, and Allies | 33 | Sep (peak) |
| 34 | Spotted Knapweed | Centaurea stoebe | Sunflowers, Daisies, Asters, and Allies | 32 | Jul (past peak) |
| 35 | Frost Aster | Symphyotrichum pilosum | Sunflowers, Daisies, Asters, and Allies | 31 | Sep (peak) |
| 36 | Bird's-Foot Trefoil | Lotus corniculatus | Legumes | 29 | Jun (past peak) |
| 37 | Hoary Alyssum | Berteroa incana | mustard family | 29 | Jun (past peak) |
| 38 | Wild Carrot | Daucus carota | carrot family | 29 | Jul (past peak) |
| 39 | Tall Bellflower | Campanulastrum americanum | bellflower family | 29 | Jul (past peak) |
| 40 | Common Blue Wood Aster | Symphyotrichum cordifolium | Sunflowers, Daisies, Asters, and Allies | 27 | Sep (peak) |
| 41 | Common Yarrow | Achillea millefolium | Sunflowers, Daisies, Asters, and Allies | 26 | Jun (past peak) |
| 42 | Allegheny monkeyflower | Mimulus ringens | lopseed family | 26 | Jul (past peak) |
| 43 | Creeping Bellflower | Campanula rapunculoides | bellflower family | 26 | Jul (past peak) |
| 44 | Purple Coneflower | Echinacea purpurea | Sunflowers, Daisies, Asters, and Allies | 25 | Aug (past peak) |
| 45 | Blue Vervain | Verbena hastata | Verbena Family | 25 | Jul (past peak) |
| 46 | Horseweed | Erigeron canadensis | Sunflowers, Daisies, Asters, and Allies | 25 | Aug (past peak) |
| 47 | fen grass of Parnassus | Parnassia glauca | staff-vine family | 24 | Aug (past peak) |
| 48 | Purple Crownvetch | Securigera varia | Legumes | 24 | Jun (past peak) |
| 49 | Pickerelweed | Pontederia cordata | Pickerelweeds | 23 | Jul (past peak) |
| 50 | American white waterlily | Nymphaea odorata | Waterlily Family | 21 | Jul (past peak) |