Taxonomy

Division:

Magnoliophyta | - Flowering plants

Family:

Onagraceae

Genus:

Oenothera

Species:

Oenothera spachiana

USDA Symbol:

OESP

Growth Characteristics

Life Cycle:

Annual

Growth Habit:

Forb/herb

Height:

60 cm

Light Requirements:

Full Sun

Drought Tolerance:

High

Bloom Months:

may,jun,jul,aug

Bloom Colors:

yellow

Wildlife Benefits

Bees:

★☆☆☆☆ Documented bee visitation (GBIF)

Butterflies & Moths:

★☆☆☆☆ Documented Lepidoptera association (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, butterflies

Deer Resistant:

Yes

Fragrant:

Yes

Fire Ecology:

Fire adapted — tolerates or benefits from fire

Fire Notes:

Resprouts from rootstock following fire; typical of prairie and grassland evening primroses.

Soil Requirements

Soil Type:

sandy, well-drained, nutrient-poor soil

pH:

6.0 - 7.5 (slightly acidic to neutral)

Drainage:

excellent drainage required

Moisture:

dry to moderate

Notes:

native to arid regions, prefers open sunny areas

Propagation & Germination

Stratification:

Cold/moist stratification required — 30–60 days

Germination Time:

14–30 days

Notes:

Seeds germinate best with light exposure. Cold stratification improves germination rates.

The above propagation data sourced from Claude AI