Evening Primrose

Oenothera biennis

Hosts 3 caterpillarsBird foodPollinator plant

Growing it

When	Flowers July to September; fruits September to October
Type	wildflower
Sun	Full sun, partial shade
Water	Low
Soil	pH 6–8
Hardiness	zone 3–9
Mature height	1.5 m
Mature spread	0.6 m
Spacing	0.4 m
Years to maturity	2
Bloom	Jul–Sep
Flower colour	Yellow read from a published flora
In bloom	July August September
Fruit	Sep–Oct
Native to	AB, SK

lance-shaped leaves about 12 cm long

Where it has been recorded

BothSpecimensObservations

80 squares of about 28 km, each holding at least one record. A square is not a claim that the plant grows throughout it, and an unshaded square is unrecorded rather than empty. Darker squares hold more records, which follows roads and towns as much as it follows the plant. 12 herbarium specimens and 157 field observations this project may redraw. A filled dot is a pressed sheet somebody can re-examine; a hollow ring is a photograph identified by community agreement. Where the dots are dense is where people have looked, not where the plant is commonest, and empty ground is unsurveyed rather than unoccupied. How this map is made.

Which ecoregions the records fall in

Moist Mixed Grassland south AB / SK: 62 records, high confidence
Aspen Parkland central AB / SK: 57 records, high confidence
Mid-Boreal Uplands central AB / SK: 19 records, medium confidence
Northern Continental Divide south AB: 19 records, medium confidence
Fescue Grassland south AB: 14 records, medium confidence
Boreal Transition central AB / SK: 11 records, medium confidence
Peace Lowland north AB: 4 records, low confidence
Mixed Grassland south AB / SK: 3 records, low confidence

These are counts of records collected somewhere in the region, which is the resolution of the evidence: the map above shows where inside it. A region with 3 records is not the same claim as one with three hundred, so the count travels with the region. A region missing from this list means nobody has recorded it there, which is not the same as the plant being absent. Records within 900 m of a border count for neither side, because the border is not drawn finely enough to say which one they are on. Source: GBIF occurrence search + PRESERVED_SPECIMEN pass, retrieved 2026-08-24. Boundaries digitised from the National Ecological Framework for Canada v2.2 (Ecological Stratification Working Group 1995), simplified to about 900 m for display: an outline is accurate to roughly a kilometre, not to the metre. How these counts are made.

See every observation, live and current, on GBIF or iNaturalist.

Documented animals

27 documented relationships.

nectar for

American Bumble Bee Specimen records from www.bumblebeewatch.org
Anise Swallowtail Specimen records from iNaturalist.org
Bicoloured Sweat Bee Specimen records from ecdysis.org
Brown-belted Bumble Bee Specimen records from iNaturalist.org
Confusing Bumble Bee Specimen records from www.bumblebeewatch.org
Dingy Cutworm Specimen records from iNaturalist.org
Eastern Calligrapher Specimen records from iNaturalist.org
Golden Northern Bumble Bee Specimen records from iNaturalist.org
Goldenrod Soldier Beetle Specimen records from iNaturalist.org
Monarch Specimen records from iNaturalist.org
Northern Amber Bumble Bee Specimen records from iNaturalist.org
Peck's Skipper Specimen records from iNaturalist.org
Red Admiral Specimen records from iNaturalist.org
Ruby-throated Hummingbird Specimen records from iNaturalist.org
Schinia florida Specimen records from iNaturalist.org
Silver-spotted Skipper Specimen records from iNaturalist.org
Snowberry Clearwing Specimen records from iNaturalist.org
Spotted Cucumber Beetle Specimen records from iNaturalist.org
Vespula consobrina Specimen records from iNaturalist.org

pollen for

Central Bumble Bee Clements & F. L. Long 1923
Epuraea truncatella Robertson 1929
Mallota posticata Robertson 1929
Megachile texana Robertson 1929

caterpillar host for

Polia purpurissata Specimen records from scan-bugs.org
Schinia florida Specimen records from iNaturalist.org
White-lined Sphinx Specimen records from iNaturalist.org

seed for

American Goldfinch Poelen et al. 2014

Also worth knowing

Safety

Toxicity not assessed, absence of a warning is not a guarantee of safety

Edible parts

Root, seeds, flowers, leaves, shoots

Buying it

About $8–$16 per plant (estimate), usually from a native-plant nursery. Estimate (herb default); AB retail as of 2026

Where these numbers came from

Flower detail: not verified, a genus-level estimate