Bloomipedia
Fragrant evening primrose (Oenothera cespitosa)
Photo: John Brew via iNaturalist · CC BY 4.0 · resized

Flower profile

Fragrant evening primrose

Oenothera cespitosa

Fragrant evening primrose (Oenothera cespitosa) is a low shrub in the Onagraceae family, native in the lower 48 states, blooming mostly April–June across the U.S.

Native in the lower 48

Fragrant evening primrose is a wildflower that USDA PLANTS lists as native in the lower 48 states. It's on our flower lists for 4 states, and across the U.S. it's most often seen in bloom in April–June.

15states where USDA records it
4Bloomipedia state lists include it
6,530U.S. sightings*

*iNaturalist research-grade observations, as of October 17, 2026.

On our lists for: Colorado, North Dakota, South Dakota, Utah

Quick look

Oenothera cespitosa, known commonly as tufted evening-primrose or fragrant evening-primrose, is a perennial plant of the genus Oenothera native to western North America from the western edge of the Great Plains and all parts of the Intermountain West in a wide range of dry habitats. Its flowers are open at night and fade by the next day. The species is cultivated in gardens, particularly in its native range.

  • It belongs to the Onagraceae family. iNaturalist
  • USDA PLANTS describes it as an herb (forb) / a subshrub with a perennial life cycle. USDA PLANTS
  • USDA PLANTS lists it as native in the lower 48 states and records it in 15 states. USDA PLANTS
  • NatureServe lists it as native to Colorado, Utah, South Dakota and North Dakota. NatureServe
  • In Colorado, most iNaturalist sightings of it in flower come in May–July. iNaturalist
  • In Utah, most iNaturalist sightings of it in flower come in April–June. iNaturalist
  • USDA PLANTS lists its flower color as white. USDA PLANTS
  • USDA PLANTS gives its bloom period as late spring. USDA PLANTS
  • USDA PLANTS lists a mature height of about 0.5 ft. USDA PLANTS
  • iNaturalist has 1,807 research-grade sightings of it in Colorado, ranking #90 among the 160 flowers on our Colorado list. iNaturalist
  • iNaturalist has 1,446 research-grade sightings of it in Utah, ranking #27 among the 153 flowers on our Utah list. iNaturalist
  • iNaturalist has 165 research-grade sightings of it in South Dakota, ranking #92 among the 126 flowers on our South Dakota list. iNaturalist

When does it bloom?

Flowering records by month across the U.S. (iNaturalist research-grade observations marked “Flowering”) (612 records)
Bloom time in the 4 states whose Bloomipedia list includes it
StateTypePeak bloomSightings*
ColoradoNativeMay–July1,807
UtahNativeApril–June1,446
South DakotaNativefew records (13)165
North DakotaNativefew records (8)68

Conservation status

Federal (U.S. ESA)
Not listed No U.S. Endangered Species Act listing in the USFWS ECOS database. USFWS ECOS
NatureServe global
G5 Secure worldwide. NatureServe
Colorado
No list Colorado has no state law listing endangered or threatened plants, so we show NatureServe's Colorado ranks instead. NatureServe: S5, secure in Colorado.
Utah
No list Utah has no state law listing endangered or threatened plants, so we show NatureServe's Utah ranks instead. NatureServe: SNR, not yet ranked in Utah.
South Dakota
No list South Dakota's endangered and threatened list (ARSD 41:10:02) covers animals only, so we show NatureServe's South Dakota ranks for plants. NatureServe: SNR, not yet ranked in South Dakota.
North Dakota
No list North Dakota has no state law listing endangered or threatened plants, so we show NatureServe's North Dakota ranks instead. NatureServe: SNR, not yet ranked in North Dakota.
Rare elsewhere
Other states where NatureServe ranks it rare or missing: WA (S2). (S1 critically imperiled, S2 imperiled, SH possibly extirpated, SX presumed extirpated.)

Checked October 17, 2026. Rankings and lists can change, so follow the links for the latest.

Can you eat it?

For peopleNot well documented

None of the sources we checked (NC State Extension (no page for this plant), USDA PLANTS) say whether it's edible or poisonous for people.

For petsNot well documented

It isn't on the ASPCA plant list.

🌿 Never eat a wild plant unless you're certain of its ID; this isn't medical advice. Worried about a person? Call Poison Control at 1-800-222-1222. Worried about a pet? Call your vet.

Where does it grow?

USDA PLANTS records fragrant evening primrose in 15 states.

recorded by USDA PLANTS on our state lists not recorded

See the full list of states

Arizona, California, Colorado, Idaho, Montana, Nebraska, Nevada, New Mexico, North Dakota, Oregon, South Dakota, Texas, Utah, Washington, Wyoming.

Colorado counties with USDA records: Archuleta, Boulder, Clear Creek, Conejos, Custer, Delta, Dolores, Douglas, Eagle, El Paso, Elbert, Fremont, Garfield, Grand, Gunnison, Huerfano, Jackson, Jefferson, La Plata, Lake, Larimer, Las Animas, Lincoln, Logan, Mesa, Mineral, Moffat, Montezuma, Montrose, Otero, Park, Rio Blanco, Rio Grande, Routt, Saguache, San Miguel, Summit, Teller, Weld.

Utah counties with USDA records: Beaver, Box Elder, Cache, Carbon, Daggett, Davis, Duchesne, Emery, Garfield, Grand, Iron, Juab, Kane, Millard, Morgan, Piute, Salt Lake, San Juan, Sanpete, Sevier, Summit, Tooele, Uintah, Utah, Wasatch, Washington, Wayne, Weber.

South Dakota counties with USDA records: Brule, Custer, Dewey, Fall River, Haakon, Harding, Jackson, Lyman, Meade, Mellette, Pennington.

Growing conditions

USDA PLANTS gives Fragrant evening primrose a high shade tolerance, high drought tolerance and low moisture use. It is rated for soil pH 6.5 to 8.0 and winter lows down to -13 °F.

Shade tolerance
High
Drought tolerance
High
Moisture use
Low
Soil textures it is adapted to
coarse, medium
Soil pH range
6.5 to 8.0
Minimum temperature tolerated
-13 °F
Frost-free days needed (minimum)
140
Annual precipitation range
7 to 69 inches
Minimum root depth
6 inches
Salinity tolerance
Medium
Fertility requirement
Low
Growth rate
Rapid
Lifespan
Short
Active growth period
Spring and Summer
Fruit or seed
Brown · Summer to Fall
Can be propagated by
container, seed
Commercial availability
Contracting Only

From the USDA PLANTS characteristics data for OECA10. USDA ratings are general guidance for the species, not a guarantee for your garden.

Names, range and relatives

Native status by region (USDA PLANTS): Canada: Native; Lower 48 states: Native.

County records: USDA PLANTS lists it in 262 counties across 14 states; the most are in Colorado (39), Montana (34), Idaho (29).

Other Oenothera on Bloomipedia (11): Pinkladies, Common evening-primrose, Cutleaf evening primrose, Scarlet beeblossom, Birdcage evening primrose, Bigfruit evening primrose, Pale evening primrose, False gaura, Yellow sundrops, Fourpoint evening primrose.

More from the Onagraceae family (19 on Bloomipedia; most observed first): Fireweed, California fuchsia, Broadleaf enchanter's nightshade, Elegant clarkia, Sun cup, Dwarf fireweed, Peruvian primrose-willow, Golden suncup.

More Colorado flowers

Fireweed (Chamaenerion angustifolium)

Fireweed

Chamaenerion angustifolium

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🌼 Blooms in CO: July–August
Scarlet beeblossom (Oenothera suffrutescens)

Scarlet beeblossom

Oenothera suffrutescens

Native

🌼 Blooms in CO: May–June
Great mullein (Verbascum thapsus)

Great mullein

Verbascum thapsus

Introduced

🌼 Blooms in CO: July–October

Sources