evening primrose
Oenothera speciosa
evening primrose (Oenothera speciosa) is a Colorado-native perennial suited to the Colorado Front Range. It matures to about 12 to 18 in tall and 6 to 12 in wide, needs low to medium water, and prefers full sun. Fire-wise zone 1-2 perennial; CSU 6.305 score 8.0 of 10.
Colorado nativeOn the CSFS firewise listlow to medium water12 to 18 in tall and 6 to 12 in wideXeric / water-wiseLow ignitability: OK 0-30 ft from the house, CSU score 8/10
Photos
- Photo 1: "Turkey (Istanbul)- Oenothera speciosa field" by ustung is licensed under CC BY 2.0. To view a copy of this license, visit https://creativecommons.org/licenses/by/2.0/.
- Photo 2: "Oenothera speciosa" by wallygrom is licensed under CC BY-SA 2.0. To view a copy of this license, visit https://creativecommons.org/licenses/by-sa/2.0/.
- Photo 3: "Turkey (Istanbul)- No enough place for daisies due to Oenothera speciosa invasion" by ustung is licensed under CC BY 2.0. To view a copy of this license, visit https://creativecommons.org/licenses/by/2.0/.
- Photo 4: "Oenothera speciosa - Pinkladies" by FritzFlohrReynolds is licensed under CC BY-SA 2.0. To view a copy of this license, visit https://creativecommons.org/licenses/by-sa/2.0/.
- Photo 5: "Oenothera speciosa 5" by Stan Shebs is licensed under CC BY-SA 3.0. To view a copy of this license, visit https://creativecommons.org/licenses/by-sa/3.0/.
- Photo 6: ZooFari
At a glance
Will it survive here?
- Hardiness zones
- USDA 4 to 8
- Water needs
- low to medium water
- Sun
- Best in full sun.
- Soil
- clay, loam, sandy
- Soil pH
- 6.5 to 8.0
- Hail tolerance
- high
- Wind tolerance
- high
- Salt tolerance
- moderate
- Site uses
- Slopes & erosion control
How big, what shape?
- Mature size
- 12 to 18 in tall and 6 to 12 in wide
- Planting spacing
- ~8 to 12 in apart
What it looks like, and when
- Bloom time
- mid spring, mid summer
- Bloom color
- white, pink
- Bloom length
- Long (several weeks)
- Foliage
- Deciduous
Who else benefits
- Pollinator value
- high
- Deer
- Not rated
- Colorado native
- Yes
- Native ecoregion
- shortgrass prairie, foothills
Also worth knowing
- Fire rating
- Low ignitability: OK 0-30 ft from the house, CSU score 8/10
Things to know before you plant
- Spreads aggressivelyPink evening primrose, aggressive rhizomes, hard to remove
Planting & establishment
Deep-water first season to establish, then minimal water needed.
Frequently asked questions
- Is evening primrose good for the Colorado Front Range?
- Yes, evening primrose is a well-suited perennial for Colorado's Front Range.
- What should I know before planting evening primrose?
- The main things to know: Pink evening primrose, aggressive rhizomes, hard to remove
- How big does evening primrose get?
- It matures to about 12 to 18 in tall and 6 to 12 in wide.
- How far apart do I plant evening primrose?
- Space evening primrose about 8 in apart for a faster, fuller bed, or up to 12 in apart for a looser planting.
- Is evening primrose hardy on the Front Range?
- evening primrose is hardy in USDA 4 to 8. The Colorado Front Range spans roughly USDA 4b to 6a, so it is well within range.
- How much water does evening primrose need?
- It needs low to medium water once established.
- Is evening primrose native to Colorado?
- Yes. It is a Colorado native.
- Is evening primrose a good firewise plant near the house?
- evening primrose is rated 8 of 10 in CSU Extension Fact Sheet 6.305 (2025), where higher means less ignitable, so it can go within 0 to 5 feet of the house as well as out to 30 feet when kept watered and tidy. This is general guidance based on CSU Extension Fact Sheet 6.305 (2025), not a guarantee that any plant won't burn, a well-irrigated, well-maintained plant is the goal. Follow CSU Extension defensible-space guidance and check with your local fire district before planting in the wildland-urban interface.
- How long does evening primrose bloom?
- evening primrose blooms for several weeks, a long-season performer on the Front Range. Bloom timing shifts a week or two with elevation and spring weather.
