Quick answer: 44 native Colorado plants have a recorded bloom range that includes September.
44 species
- Apache plume Fallugia paradoxa · 8 states
- Aspen fleabane Erigeron speciosus · 7 states
- Big bluestem Andropogon gerardii · 41 states
- Big sagebrush Artemisia tridentata · 14 states
- Black-eyed Susan Rudbeckia hirta · 44 states
- Blackfoot daisy Melampodium leucanthum · 6 states
- Blue grama Bouteloua gracilis · 19 states
- Buffalograss Bouteloua dactyloides · 19 states
- Butterflyweed Asclepias tuberosa · 40 states
- Cardinal flower Lobelia cardinalis · 41 states
- Chocolate flower Berlandiera lyrata · 6 states
- Colorado four o'clock Mirabilis multiflora · 7 states
- Common gaillardia (blanketflower) Gaillardia aristata · 11 states
- Common sneezeweed Helenium autumnale · 40 states
- Common sunflower Helianthus annuus · 18 states
- Common yarrow Achillea millefolium · 47 states
- Cutleaf coneflower Rudbeckia laciniata · 43 states
- Dotted blazing star Liatris punctata · 17 states
- Fireweed Chamerion angustifolium · 37 states
- Giant red paintbrush Castilleja miniata · 13 states
- Harebell Campanula rotundifolia · 35 states
- Hooker's evening primrose Oenothera elata · 14 states
- Indiangrass Sorghastrum nutans · 37 states
- Little bluestem Schizachyrium scoparium · 42 states
- Mexican hat Ratibida columnifera · 17 states
- Nettleleaf giant hyssop Agastache urticifolia · 9 states
- Pearly everlasting Anaphalis margaritacea · 38 states
- Purple prairie clover Dalea purpurea · 18 states
- Rocky Mountain bee plant Peritoma serrulata · 26 states
- Rocky Mountain zinnia Zinnia grandiflora · 6 states
- Rubber rabbitbrush Ericameria nauseosa · 17 states
- Scarlet bugler Penstemon barbatus · 2 states
- Scarlet gilia Ipomopsis aggregata · 13 states
- Scarlet globemallow Sphaeralcea coccinea · 12 states
- Seep monkeyflower Erythranthe guttata · 15 states
- Shrubby cinquefoil Dasiphora fruticosa ssp. floribunda · 23 states
- Sideoats grama Bouteloua curtipendula · 38 states
- Spotted beebalm Monarda punctata · 29 states
- Sulphur-flower buckwheat Eriogonum umbellatum · 10 states
- Swamp milkweed Asclepias incarnata · 37 states
- Switchgrass Panicum virgatum · 43 states
- Western yarrow Achillea millefolium var. occidentalis · 18 states
- Woolly paperflower Psilostrophe tagetina · 7 states
- Wyoming Indian paintbrush Castilleja linariifolia · 9 states
September in a Colorado native garden
September is a quieter month in Colorado: 44 of the state's 100 native plants flower in September, compared with 75 at the June peak. That makes these plants valuable for keeping color, and food for pollinators, going outside the main season.
15 finish in September, including Butterflyweed, Colorado four o'clock and Common gaillardia (blanketflower), so this is the last chance to see them in flower.
40 of them grow in full or partial sun and 8 tolerate shade, so there are options for open beds and woodland edges alike. 19 stay under about 3 feet, including Aspen fleabane and Black-eyed Susan, which suits borders and small yards. For wildlife, 38 support pollinators, 24 provide food or cover for birds and 13 are caterpillar host plants.
29 of the 44 have a seed or plant listing we verified as the wild species. Be careful buying Apache plume, Black-eyed Susan, Common yarrow: 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