Taxonomy

Division:

Magnoliophyta | - Flowering plants

Family:

Onagraceae

Genus:

Oenothera

Species:

Oenothera coloradensis

USDA Symbol:

OECO

Growth Characteristics

Life Cycle:

Biennial

Growth Habit:

Forb/herb

Height:

100 cm

Light Requirements:

Full Sun

Drought Tolerance:

Low

Bloom Months:

jun,jul,aug,sep

Bloom Colors:

yellow

Wildlife Benefits

Bees:

★☆☆☆☆ Documented bee visitation (GBIF)

Butterflies & Moths:

★☆☆☆☆ Documented Lepidoptera association (GBIF)

Caterpillars:

★☆☆☆☆ Recorded caterpillar host plant (HOSTS Database)

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)

Host Plant for Caterpillars

Garden & Ecology Notes

Wildlife Value:

bees, butterflies

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:

Prefers open, sunny habitats with minimal competition.

Propagation & Germination

Stratification:

Cold/moist stratification required — 30–60 days

Germination Time:

14–30 days

Notes:

Seeds benefit from cold stratification for 4-8 weeks to break dormancy; surface sow on moist soil and keep warm after stratification.