Evening Primrose

Table of Contents

1. Description
2. Origin
3. Uses
4. Culture
5. Sources
6. Thanks to...

Oenothera biennis
Family: Onagraceae

Common names: evening primrose, night willow herb, evening star, fever plant, field primrose, King's cure all, scabish, tree primrose, primrose, moth's moonflower.

Evening primrose is a biennial plant with numerous, crinkled, lance-shaped leaves and green stems with red splotches. Flowers bloom after sunset andare yellow, fragrant with four broad petals. Grows up to 20 cm. Flowers are produced all along the stalk and bloom is continuous from June through autumn.

First-year plants are a spreading rosette.

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Origin

North America: Evening primrose was used by the North American Indians for a variety of medical problems. Common wildflower in fields, ditches and waster places. This plant is grown commercially for its seed oil which is rich in GLA (gamma linoleic acid) fatty acids; cis-linoleic (70%), cis-gammalinolenic acid (9%).

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Uses Evening Primrose and Claims

• Culinary: none
• Medicinal: above ground parts are thought to have astringent properties, used to treat whooping cough, digestive problems, asthma etc; oil has been applied externally to treat itchy skin conditions, internally to lower blood pressure, prevent clumping of the platelets, premenstrual problems. Dangerous to take if suffering from epilepsy.
• Industrial: none

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Culture

• Propagation: Relatively easy to propagate from seeds. Germination takes 15 to 20 days. When large enough to handle thin the seeds to 30 cm. (12 inches). Sow seed less than 1.5 cm deep indoors in August for spring transplanting and bloom the first year. Direct seed in the field at 4-20 kg/ha. Sow seed 2.5 cm deep in April. Transplant to 7.5m cm apart in September.
• Cultivation: Thrives in full sun. Self-seeds freely. Tendency to develop powdery mildew on leaves and root rot in wet conditions. Needs a long, hot, dry season for seds to mature. Seed shatters easily. Irrigation may improve yields.
• Soil Type: well drained sandy soil and a pH of 6 to 8.
• Harvest: Collect seeds when ripe and rpess for oil. Seeds should contain 30-40% moisture.

CAUTION: This crop should not be grown commercially without a contract.

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Sources

• Bremness, L. 1994. Herbs. Dorling Kindersley Ltd. London.
• Chevallier, A. 1996. The Encyclopedia of Medicinal Plants. Reader's Digest Association. Westmount, Que.
• Foster, S, J.A. Duke. 1990. Eastern/Central Medicinal Plants. Houghton Mifflin. New York.
• Richters Herb Catalogue. Richters. Goodwood Ontario, Canada.
• Keville, K. Herbs an Illustrated Encyclopedia. Friedman/Fairfax publishers. New York. 1994.
• McVicar J. Jekka's Complete Herb Book. Raincoast Books, Vancouver. 1998.
• Saskatchewan Herb and Spice Produciton Manual. 2000. Saskatchewan Herb and Spice Associaiton.

Thanks to

This demonstration garden was a result of the efforts of Dr. Alan McKeown, Vegetable Scientist, University of Guelph and was made possible with grants from the Ontario Fruit and Vegetable Growers Association and the Tobacco Diversification Program.

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