Evening primrose

Oenothera biennis L.

Family: Onagraceae (evening primrose)

John Cardina, The Ohio State University, Bugwood.org

Flower of the evening primrose

Bloom Period:
- Mid-Season,
Growth Cycle:
- Biannual,
Growth Habit:
- Forbs/Herbs,
Insect Type Attracted:
- Natural Enemy,
- Pollinator,
Light:
- Full,
- Partial,
Region:
- Northern Lower Peninsula,
- Southern Lower Peninsula,
- Upper Peninsula
Soil Moisture:
- Medium,
Height:
- 2-4ft

Natural enemies attracted

Moderately attractive: Plagiognathus politus and Orius insidiousus.

Mildly attractive: Chalcodoidea, Thomisidae, Coccinellidae, Braconidae and Nabidae.

Pollinators attracted

None collected using the vacuum sampling method, but low numbers (less than 1 bee per meter square during 5 minute visual observations) of bees were observed.

Pests attracted

Highly attractive: lygus bugs, leafhoppers, and Japanese beetles.

Mildly attractive: thrips, aphids, leaf beetles and weevils.

Plant notes

This biennial has 1-inch wide, pale-yellow flowers at the end of a bush-like plant in its second growing season (the first year after plugs are planted). It filled in well. This species bloomed from late July through mid-August. This was the seventh most attractive mid-season plant to natural enemies, with two times more natural enemies than the grass control.

Habitat

This plant tolerates full sun to partial shade, and midrange soil moisture that is neither very wet nor very dry. It naturally occurs in fields, clearings, dry, sandy roadsides and on disturbed ground.

Cultivation and management

This plant blooms in the second or third year when grown from seed. Also, it can be grown from plug material (flowers in first or second year). Evening primrose is useful in early stages of establishment of naturalized areas. Although attractive to natural enemies, this species was infested with Japanese beetle.