Quick answer: 34 native Connecticut plants have a recorded bloom range that includes September.
34 species
- Big bluestem Andropogon gerardii · 25 states
- Black-eyed Susan Rudbeckia hirta · 42 states
- Blue mistflower Conoclinium coelestinum · 26 states
- Blue vervain Verbena hastata · 11 states
- Butterflyweed Asclepias tuberosa · 37 states
- Canadian burnet Sanguisorba canadensis · 1 states
- Cardinal flower Lobelia cardinalis · 37 states
- Closed bottle gentian Gentiana andrewsii · 10 states
- Common sneezeweed Helenium autumnale · 13 states
- Common yarrow Achillea millefolium · 31 states
- Crimson-eyed rose-mallow Hibiscus moscheutos · 14 states
- Culver's root Veronicastrum virginicum · 8 states
- Cup plant Silphium perfoliatum · 17 states
- Cutleaf coneflower Rudbeckia laciniata · 21 states
- Dense blazing star Liatris spicata · 15 states
- Fall obedient plant Physostegia virginiana · 21 states
- Fireweed Chamerion angustifolium · 28 states
- Great blue lobelia Lobelia siphilitica · 32 states
- Harebell Campanula rotundifolia · 25 states
- Inkberry Ilex glabra · 4 states
- Little bluestem Schizachyrium scoparium · 23 states
- New England aster Symphyotrichum novae-angliae · 18 states
- New York ironweed Vernonia noveboracensis · 3 states
- Northern bayberry Morella pensylvanica · 2 states
- Partridgeberry Mitchella repens · 17 states
- Pearly everlasting Anaphalis margaritacea · 18 states
- Scarlet beebalm Monarda didyma · 18 states
- Seaside goldenrod Solidago sempervirens · 2 states
- Showy tick trefoil Desmodium canadense · 21 states
- Spotted beebalm Monarda punctata · 14 states
- Sweet Joe-Pye Eutrochium purpureum · 17 states
- Switchgrass Panicum virgatum · 24 states
- Trumpet vine Campsis radicans · 24 states
- Witch-hazel Hamamelis virginiana · 28 states