Onagraceae (Oenothera)

Protocol Information for:

Label_title:
Oenothera (elata)

Family Names:

Family Scientific Name:
Onagraceae

Family Common Name:
Evening primrose

Scientific Names:

Genus:
Oenothera

Species:
elata

Scientific Classification:

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Authors:

Common Synonym:

Genus:

Species:

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Other Information:

Common Name:
Hooker's evening primrose

Species Code:

Ecotype:
Seed collected at The Nature Conservancy's Dye Creek Preserve, Tehama County, California

General Distribution:
Western North America to Central America. Moist places below 2,800 m (Hickman 1993).

Known Invasiveness:

Propagation Goal:
plants

Propagation Method:
seed

Product Type:
Container (plug)

Stock Type:
Potted nursery stock

Grow Time:
8 Months

Target Specifications:
Robust rosette forms within 6-10 months.

Propagation Collection:
Fruits ripen from May through June (July). Seed may be rapidly gathered by drying fruit upside down in palstic bags.

Propagation Processing/Propagule Characteristics:
None, though clean dry seed was placed in dry, cold storage following collection and prior to sowing.

Pre-Planting Propagule Treatments:

Growing Area Preparation / Annual Practices for Perennial Crops:
Seed was directly sown into 1.5" deep flats containing a potting mixture of approximately 1:1:1:2 sand:pumice:peat moss:fir bark mixture. Flats were placed in an outdoor cold frame from late-fall though spring. Most seedlings were transplanted into various sized pots ranging from D-pots to 3x4" plastic containers (some seedlings were not transplanted) using the same potting mixture. Better growth may be obtainined during the first year by avoiding transplanting (seed directly into larger containers rather than flats).

Establishment Phase:
Initial germination was observed within 1 week; Observed germination rate was 87% for seed cold, moist stratified in vermiculite at approximately 44F.

Length of Establishment Phase:
Transplantable sprouts were established within approximately 2-4 weeks.

Active Growth Phase:
Active growth was observed following the onset of autumn rains (seed swelling) until late summer/early fall (depending on moisture and sunlight.

Length of Active Growth Phase:
Up to 10 months depending on moisture and sunlight.

Hardening Phase:
Not necessary.

Length of Hardening Phase:

Harvesting, Storage and Shipping:

Length of Storage:

Guidelines for Outplanting / Performance on Typical Sites:

Other Comments:
Flowering: Early July - November (Oswald and Ahart 2002). Seed collection: May-June (July). Transplantedseedlings showed some sign of stress and seedlings transplanted earlier showed more vigorous growth subsequent to transplanting. Seed sown directly in the field showed above and below ground growth rates comparabel too, or better than seed grown under controlled conditions in well-drained potting soils. Heavier native soils may provide better growing conditions when kept moist compared to well-drained potting soils whose moisture and temperature may fluctuate more readily. Partial funding for this project was made available by the California State University Agricultural Research Initiative (ARI).

References:
Hickman, James, Ed. 1993. The Jepson Manual: Higher Plants of California. University of California Press, Berkeley, California.; Oswald, Vern and Lowell Ahart. 2002. Selected Plants of Northern California and Adjacent Nevada. CNPS

Citation:
Leigh, Mark; Pushnik, James C.; Boul, Rachelle D.; Brown, Matthew R.; Hunt, John W.; Koenig, David A.. 2006. Propagation protocol for production of Container (plug) Oenothera elata plants Potted nursery stock; University of California - Chico Chico, California. In: Native Plant Network. URL: https://NativePlantNetwork.org (accessed 2025/07/16). US Department of Agriculture, Forest Service, National Center for Reforestation, Nurseries, and Genetic Resources.

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