Quick answer: 68 native Pennsylvania plants have a recorded bloom range that includes September.
68 species
- Balsam fir Abies balsamea · 6 states
- Big bluestem Andropogon gerardii · 41 states
- Black-eyed Susan Rudbeckia hirta · 44 states
- Blue mistflower Conoclinium coelestinum · 32 states
- Blue vervain Verbena hastata · 34 states
- Brown-eyed Susan Rudbeckia triloba · 21 states
- Bunchberry Cornus canadensis · 18 states
- Butterflyweed Asclepias tuberosa · 40 states
- Canadian burnet Sanguisorba canadensis · 20 states
- Cardinal flower Lobelia cardinalis · 41 states
- Closed bottle gentian Gentiana andrewsii · 23 states
- Common buttonbush Cephalanthus occidentalis · 29 states
- Common evening primrose Oenothera biennis · 30 states
- Common selfheal Prunella vulgaris · 25 states
- Common sneezeweed Helenium autumnale · 40 states
- Common yarrow Achillea millefolium · 47 states
- Crimson-eyed rose-mallow Hibiscus moscheutos · 28 states
- Culver's root Veronicastrum virginicum · 32 states
- Cup plant Silphium perfoliatum · 27 states
- Cutleaf coneflower Rudbeckia laciniata · 43 states
- Dense blazing star Liatris spicata · 24 states
- Devil's walking stick Aralia spinosa · 21 states
- Eastern purple coneflower Echinacea purpurea · 24 states
- Fall obedient plant Physostegia virginiana · 37 states
- Fewleaf sunflower Helianthus occidentalis · 16 states
- Fireweed Chamerion angustifolium · 37 states
- Flowering spurge Euphorbia corollata · 29 states
- Grayhead coneflower Ratibida pinnata · 26 states
- Great blue lobelia Lobelia siphilitica · 36 states
- Green-and-gold Chrysogonum virginianum · 13 states
- Groundnut Apios americana · 21 states
- Harebell Campanula rotundifolia · 35 states
- Hollow Joe-pye weed Eutrochium fistulosum · 24 states
- Indiangrass Sorghastrum nutans · 37 states
- Inkberry Ilex glabra · 14 states
- Jerusalem artichoke Helianthus tuberosus · 26 states
- Little bluestem Schizachyrium scoparium · 42 states
- Maryland goldenaster Chrysopsis mariana · 17 states
- New England aster Symphyotrichum novae-angliae · 29 states
- New York ironweed Vernonia noveboracensis · 18 states
- Orange coneflower Rudbeckia fulgida · 23 states
- Partridge pea Chamaecrista fasciculata · 30 states
- Partridgeberry Mitchella repens · 31 states
- Pearly everlasting Anaphalis margaritacea · 38 states
- Roundhead lespedeza Lespedeza capitata · 30 states
- Scarlet beebalm Monarda didyma · 25 states
- Sensitive fern Onoclea sensibilis · 26 states
- Showy goldenrod Solidago speciosa · 28 states
- Showy tick trefoil Desmodium canadense · 29 states
- Shrubby cinquefoil Dasiphora fruticosa ssp. floribunda · 23 states
- Sideoats grama Bouteloua curtipendula · 38 states
- Smooth oxeye Heliopsis helianthoides · 30 states
- Spotted beebalm Monarda punctata · 29 states
- Steeplebush Spiraea tomentosa · 22 states
- Swamp milkweed Asclepias incarnata · 37 states
- Sweet Joe-Pye Eutrochium purpureum · 33 states
- Switchgrass Panicum virgatum · 43 states
- Trumpet vine Campsis radicans · 33 states
- Virgin's bower Clematis virginiana · 27 states
- Virginia chain fern Woodwardia virginica · 24 states
- White doll's daisy Boltonia asteroides · 16 states
- White heath aster Symphyotrichum ericoides var. ericoides · 26 states
- White meadowsweet Spiraea alba · 22 states
- White snakeroot Ageratina altissima · 23 states
- White turtlehead Chelone glabra · 22 states
- Whorled milkweed Asclepias verticillata · 30 states
- Witch-hazel Hamamelis virginiana · 33 states
- Yellow passionflower Passiflora lutea · 21 states
September in a Pennsylvania native garden
September is a quieter month in Pennsylvania: 68 of the state's 308 native plants flower in September, compared with 192 at the May peak. That makes these plants valuable for keeping color, and food for pollinators, going outside the main season.
3 start blooming in September, including Balsam fir, White heath aster and Witch-hazel. 34 finish in September, including Blue vervain, Bunchberry and Butterflyweed, so this is the last chance to see them in flower.
54 of them grow in full or partial sun and 27 tolerate shade, so there are options for open beds and woodland edges alike. Sizes run from low plants like Black-eyed Susan and Butterflyweed to trees such as Balsam fir and Devil's walking stick. For wildlife, 57 support pollinators, 44 provide food or cover for birds and 23 are caterpillar host plants.
61 of the 68 have a seed or plant listing we verified as the wild species. Be careful buying Black-eyed Susan, Common yarrow, Crimson-eyed rose-mallow: common listings for these are often a bred variety or a different species.
Good places to start
Verified wild-species listings that take sun and are widely native, so they are forgiving first plants.
- Cutleaf coneflower Rudbeckia laciniata · Sun, Part Shade, Shade · blooms Jul-Oct
- Little bluestem Schizachyrium scoparium · Sun, Part Shade · blooms Jun-Dec
- Big bluestem Andropogon gerardii · Sun, Part Shade · blooms Aug-Nov