Yellow Evening Primrose
Oenothera flava
Also known as: Murdock's Evening Primrose
- Native to:
- Canada, Mexico, United States
Chris Light
Taxonomy
- Division:
- Magnoliophyta | - Flowering plants
- Family:
- Onagraceae
- Genus:
- Oenothera
- Species:
- Oenothera flava
- USDA Symbol:
- OEFL
Growth Characteristics
- Life Cycle:
- Perennial
- Growth Habit:
- Forb/herb
- Height:
- 15 cm
- Light Requirements:
- Full Sun
- Drought Tolerance:
- High
- Bloom Months:
- may,jun,jul,aug
- Bloom Colors:
- yellow
Wildlife Benefits
- Bees:
- ★☆☆☆☆ Documented bee visitation (GBIF)
Keystone Species Ranking
- Caterpillar Keystone:
- ★★☆☆☆ Butterfly & moth species supported by this genus (NWF)
- Pollen Specialist Bee Keystone:
- ★★★☆☆ Native pollen specialist bee species supported by this genus (NWF)
Garden & Ecology Notes
- Wildlife Value:
- bees, moths
- Deer Resistant:
- Yes
- Fragrant:
- Yes
- Fire Ecology:
- Fire adapted — tolerates or benefits from fire
- Fire Notes:
- Resprouts from taproot following fire; common in fire-maintained grasslands and prairies.
Soil Requirements
- Soil Type:
- sandy, well-drained, nutrient-poor soil
- pH:
- 6.0 - 8.0 (slightly acidic to neutral)
- Drainage:
- excellent drainage required
- Moisture:
- dry to moderate
- Notes:
- native to arid and semi-arid regions
Propagation & Germination
- Stratification:
- Cold/moist stratification required — 30–90 days
- Germination Time:
- 14–30 days
- Notes:
- Seeds may germinate erratically; light may improve germination rates.
The above propagation data sourced from Claude AI
Pre-treatment: Seeds are imbibed in water for 4 hours and undergo a 90 day cold, moist stratification at 1 to 3°C in the refrigerator.
Establishment: Seeds are hand collected in August when capsules begin to split open. Seeds are brown at maturity. They are collected in paper bags and kept in a well ventilated drying shed prior to cleaning.
Source: npn.rngr.net
ORGHPS Germination Guide: Sow @ 20C. Germinates within 3 months.