Evening Primrose [Oenothera biennis]

The biennial evening primrose is a versatile medicinal plant that opens its flowers at sunset, making it an important source of food for insects. Its healing evening primrose oil is well known for its ability to help with skin conditions, period pain, and arthritis, among other things. Ideal for direct sowing, no pot cultivation, sowing spring-summer, good for mixed cultivation, harvesting the flowers and leaves.

 Description 
The evening primrose is a biennial, versatile medicinal plant from North America that has been used in Central Europe since the 17th century. In the wild, it grows primarily in sunny ruderal areas, roadsides, and gravelly or stony surfaces such as stream banks and railway tracks. The unique plant develops long inflorescences from a large rosette of leaves with flowers that open at sunset and bloom until the next midday. Because it blooms for a long time, this versatile species is an important source of food for insects. All parts of the plant are edible. The strong, starchy, and fleshy roots have a spicy aroma and can be prepared like salsify or grated into salads. The taste of the roots is reminiscent of horseradish and celery. The high-quality and well-known healing evening primrose oil is made from the seeds, which is used for skin conditions such as neurodermatitis, period pain, rheumatic complaints, arthritis, or as an additive and active ingredient in cosmetic creams.

 General information 
Plant family: Onagraceae
Life cycle: Biennial
Days to harvest: 100 days
Plant height approx.: 100 cm
Root type: Deep rooter
Nutrient requirements: Low
Water requirements: Low
Winter hardiness: Up to -34°C
Location: Sunny
Soil: Permeable, sandy, gravelly, loamy, humus

pH value: 6.5 to 7.5

 Sowing and planting information 
Germination type: Light germinator
Sowing depth: 0 cm
Optimal germination temperature: 16-20 °C
Germination time: 14-21 days
Plant and row spacing: 25x25 cm

Germination ability of seeds: 70 years

 Mixed culture 
Optimal mixed culture: -
Unfavorable mixed culture: -

 Sowing by climate zone 
Subtropic climate (Mediterranean) (e. g. B. Portugal, Spain, Italy)
Direct sowing from March to May is recommended. The plants should ideally be planted in a sunny location.
Moderate climate (e. g. B. Germany, Switzerland, Poland)
Direct sowing from April to May is recommended. The plants should ideally be planted in a sunny location.

 General recommendations 
Direct sowing is recommended. After germination, thin out the plants to the specified plant spacing.
Evening primrose ideally prefers soil that is nutrient-rich, moist, permeable, sandy and gravelly, and contains loam and humus. The plants grow on almost all types of soil. They do not tolerate waterlogging.

 Additional tips 
Sows itself abundantly. Later sowing is also possible. In order to quickly obtain a fine, crumbly and permeable soil with good nutrient and water storage capacity, additional incorporation of biochar and primary rock flour is recommended.

 Type of propagation 
Propagation occurs via seeds.

 Plant care 
To prevent self-seeding, it is necessary to cut off the withered flower heads. Regular watering results in faster growth. No fertilization necessary.

 Other names 
Botanical names: Oenothera biennis
English names: Evening Primrose
German names: Nachtkerze, Rapontika, Nachtblume, Abendblume, Eierblume, Schinkenkraut, Schinkenwurz, Stolzer Heinrich, Hustenblume, Süßwurzel, Gelbe Rapunzel
Portuguese names: Onagra
Spanish names: Onagra
French names: Onagre

 Origin 
Country: Germany