Illinois in bloom

Illinois bloom calendar

Darker = more flowering sightings that month. Based on iNaturalist research-grade observations in Illinois marked “Flowering,” as of October 17–23, 2026. Garden flowers have few records because research-grade data leaves out planted ones.

Families on this list

The plant families with the most flowers on this list, from iNaturalist taxonomy. Within each family, the most-observed flowers come first.

• Rosaceae (26): Roses (genus Rosa), Multiflora rose, Mock strawberry, Black raspberry, Common ninebark, Downy serviceberry, Black chokeberry, Sweet cherry and 18 more
• Asteraceae (22): Common yarrow, White snakeroot, Chicory, Black-eyed Susan, Bull thistle, Common dandelion, Creeping thistle, Late boneset and 14 more
• Fabaceae (11): White clover, Red clover, Eastern redbud, Purple crownvetch, Bird's-foot trefoil, Partridge pea, White sweetclover, Leadplant and 3 more
• Lamiaceae (9): Common selfheal, Ground-ivy, Red deadnettle, Henbit deadnettle, Wild bergamot, American germander, Common motherwort, Obedient plant and 1 more
• Caprifoliaceae (6): Amur honeysuckle, Common snowberry, Cutleaf teasel, Seven-son flower, Weigela, Glossy abelia
• Oleaceae (6): Purple lilac, Border forsythia, Japanese tree lilac, Meyer lilac, Chinese fringetree, Hairy lilac
• Viburnaceae (5): American black elderberry, Japanese snowball viburnum, Nannyberry, Arrowwood viburnum, Koreanspice viburnum
• Ranunculaceae (5): Lesser celandine, Rue anemone, Red columbine, Sharp-lobed hepatica, False rue anemone
• Hydrangeaceae (5): Sweet mock orange, Bigleaf hydrangea, Panicle hydrangea, Mountain hydrangea, Slender deutzia
• Apiaceae (4): Queen Anne's lace (wild carrot), Common cowparsnip, Rattlesnake master, Golden alexanders
• Aquifoliaceae (4): American holly, Winterberry, Inkberry, Japanese holly
• Asparagaceae (3): Solomon's plume (false Solomon's seal), Star-flowered lily-of-the-valley, Siberian squill
• Apocynaceae (3): Common milkweed, Butterfly milkweed, Swamp milkweed
• Brassicaceae (3): Garlic mustard, Dame's rocket, Cut-leaved toothwort
• Ericaceae (3): Catawba rhododendron, Japanese andromeda, Satsuki azalea

Shortlists by growing conditions

Flowers on this list whose USDA PLANTS characteristics data gives the rating shown. USDA only rates some species, so these lists are not complete.

• High drought tolerance (12): Eastern redbud, Butterfly milkweed, Purple crownvetch, White sweetclover, Cutleaf coneflower, Grey-headed coneflower, Foxglove beardtongue, Common snowberry, Leadplant, Stiff-leaved goldenrod, New Jersey tea, Common ninebark
• High moisture use (suits wet spots) (19): Chicory, Jack-in-the-pulpit, Eastern skunk cabbage, Buttonbush, Wild bergamot, Virginia bluebells, Common cowparsnip, Bird's-foot trefoil, Swamp milkweed, American germander, Southern magnolia, Butterweed and 7 more
• Rapid growth rate (21): American pokeweed, Common selfheal, Red clover, Chicory, Black-eyed Susan, Common dandelion, Dame's rocket, American black elderberry, Partridge pea, Blue phlox, White sweetclover, Black raspberry and 9 more

How we picked these flowers

We started from iNaturalist's research-grade sightings in Illinois, most-observed first, left out grasses, sedges, trees and other plants with tiny or wind-pollinated flowers (plus poison ivy), kept at most three species per genus, and added Illinois's official flowers, plus flowering shrubs and trees with at least 3 garden or 10 wild iNaturalist records in Illinois and popular garden flowers that iNaturalist users record growing in Illinois. Every flower needs a CC0 or CC BY photo.

Rare plant list: Illinois List of Endangered and Threatened Flora (17 Ill. Adm. Code 1050), per the Endangered Species Protection Board's 2025 checklist
Invasive plant list: Illinois Official List of Exotic Weeds (17 Ill. Adm. Code 1100.30, Illinois Exotic Weed Act)