Evening Primrose [Oenothera biennis]

Evening primrose is a biennial, diverse medicinal plant native to North America that has been used in Central Europe since the 17th century. In the wild, it prefers to be found in sunny ruderal areas, roadsides and gravelly or gravelly 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 nutrition 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 used grated in 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 diseases such as neurodermatitis, menstrual 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: Weak eater
Water requirements: Low
Winter hardiness: Up to -34 °C
Location: Sunny
Soil: Permeable, dry, loamy, gravelly, sandy, humus

pH value: 6.5 to 7.5

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

Optimal mixed culture: 
Unfavorable mixed culture: 

Subtropic climate (Mediterranean) (e. g. B. Portugal, Spain, Italy)
Sow directly outdoors from March to May or pre-cultivate in small pots from March to June.

Moderate climate (e. g. B. Germany, Switzerland, Poland)
Sow directly outdoors from April to May or pre-cultivate in small pots from March to May.

General
Sow directly in rows. When pre-cultivating, sow the seeds in small pots and let the seedlings grow to the first visible evening primrose leaves. Then plant the pregrown plants from the pots directly into the open field. The seedlings are planted in the bed from the 2nd pair of leaves after the cotyledons.
Evening primrose prefers a sunny location with a permeable, humus-rich, gravelly and sandy loam soil. The plants grow on almost all soils. Prepare the soil with seasoned animal manure. Avoid waterlogging.

Additional tips
Sows itself abundantly. Later sowing is also possible. In order to quickly obtain a fine, crumbly and permeable soil, we recommend additional incorporation of biochar and primary rock powder.

Type of propagation
It spreads via seeds.

Plant care
To prevent self-sowing, cut off the spent inflorescences. Regular watering causes faster growth. Beds prepared with animal manure and planting in mixed culture replace additional fertilizer.

Germination ability of seeds: 70 years

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