Evening primrose – characteristics, cultivation, use and curative effects

Evening Primrose
Evening Primrose

The evening primrose is today considered one of the best medicinal herbs for numerous skin complaints. The seeds containing the evening primrose oil are rich in gamma-linolenic acids. These can boost certain hormone productions and activate the body’s defenses. The plant with the impressive yellow flowers, which is also referred to names such as sun drop, evening star or German rampion, also cuts a good figure in the kitchen .

Profile of Evening primrose:

Scientific name: Oenothera biennis

Plant family: evening primrose family, willowherb family

Other names: evening star, sun drop, weedy evening primrose, German rampion, hog weed, King’s cure-all, fever-plan

Sowing time / Planting time: April – May

Flowering period: June – October

Harvest time: July – October

Location: partially shaded to sunny

Soil quality: sandy and nutrient-poor soils

Use as a medicinal herb: skin complaints, eczema, atopic dermatitis, PMS, rheumatism, diarrhea

Use as aromatic herb: as vegetables similar to black salsify

Plant characteristics and classification of Evening primrose

Origin and distribution of the evening primrose

The common evening primrose is native to North America. Around the middle of the 17th century, the plant was introduced by sea to Europe and quickly attracted a lot of attention in many gardens as an ornamental plant. Since the plant can spread quite quickly and colonize many habitats, it was found in wilderniss in no time in many places in Europe. It is considered a classic neophyte, a plant that today colonizes other parts of the world through human influence.

In Germany and Europe, the evening primrose escaped and can be found in many locations. Here one finds the herbaceous plant as well on footpaths, on roadsides, on brownfields, on railway embankments or on barren meadows.

Systematic classification of common evening primrose

In botany, the common evening primrose (Oenothera biennis) with about 650 other species forms the family of evening primrose family (Onagraceae). Amongst others, this family includes many well-known ornamental plants such as willowherb, summer azalea, fuchsia or the enchanter’s nightshade. In the narrower the common evening primrose belongs to the genus evening primrose (Oenothera), which probably contains more than 180 species. Something better known here are the species redsepal evening primrose and the Oakes’s evening primrose, which are occasionally used as an ornamental plant.

Characteristics of the evening primrose

The common evening primrose is a typical herbaceous plant, which can reach stature heights between 150 and 180 cm (59 and 71 inches) in optimal location conditions. However, escaped species are usually much smaller and usually grow between 80 cm and 100 cm (31 and 40 inches). The plant is biennial and forms a characteristic rhizome with whitish, large taproots. The roots are usually only slightly pilosed and form only a few to no lateral roots.

The leaves must be distinguished in basic leaves and stem leaves. The leaves on the bottom are usually ovate, oblong and arranged in a leaf rosette, which is typical for the first year of life of the plant. In the following year the upright stems grows from the rosette, which may sometimes be edged and colored reddish in the lower area. On the stem grow the much smaller stem leaves, which have only a short stem. Characteristic for the hairless leaves are the leaf veins. The main vein, which goes from the base of the leaf to the petiole, is reddish in color, whereas the lateral vein tracts are rather colorless.


During flowering, which usually lasts from mid-June to early October, egg-yolk-yellow flowers develop that can reach a diameter of up to 2.5 cm (1 inch). The pedicels evolve from the same leaf axes, where the stem leaves are sitting. The hermaphrodite flowers of the evening primrose have a pleasant, sweet scent and are arranged in so-called flower clusters. The sepals of the flowers are usually greenish to yellowish.

After flowering, elongated ovaries evolve from the inflorescences, resulting in up to 5 cm long (2 inches) and four-edged capsule fruits. Each fruit contains two fruit compartments containing up to 200 seeds. The seeds have a mostly dark brown color. Each plant can produce more than 20,000 seeds, which explains why the plant can spread rapidly over short periods of time.

Evening Primrose - seedling
Evening Primrose – seedling

Evening primrose – cultivation, sowing and care

Because of its beautiful flowers and their healing properties, the evening primrose is popular with some gardeners. The well-known herb adapts very well to herbal gardens, which only have low demands on the location. The cultivation of the plant is relatively easy, especially since it has relatively few demands on location and soil.

For the cultivation I would like to briefly summarize the most important points:

  • Habitat: half shady to sunny
  • Sowing: end of April to beginning of May
  • Fertilizer: not required in openground
  • Cultivar: both outdoor and tub
  • Watering: relatively undemanding, occasionally watering soil
  • Pests: Fungus not uncommon (Mildew or Septoria)
  • Wintering: not necessary, because frost tolerant

Site conditions

The common evening primrose grows in both sunny and partially shaded locations. However, sunny locations are preferred and provide better plant development. The evening primrose likes especially sandy and calcareous soil types with low nutrient supply. If only clayey soils are available, they should be mixed with about 50 percent sand. It is also possible to cultivate the plant in a bucket with a good herbal soil, which should also be mixed with sand (about 30 percent).


The best times to put the seeds into the garden bed are the months April / May or July / August. The seeds should no longer be exposed to frost, as the seedlings otherwise take great damage. If the seeds are seeded in late April to early May, the plant may only be one year old. The Seed need light to germ and should therefore not be pushed more than one centimeter (0.4 inches) into the ground and only slightly covered. After about 12 to 16 days, the seedlings usually appear.

When planting several plants, a planting distance of about 30 to 40 cm (12 to 15 inches) per plant should be maintained. Smaller distances increase the development of diseases or pest infestation. If the evening primrose is to grow in plant pots, deep and large-volume pots are recommended, as the it forms deeper roots. Potted cultures are often much smaller than plants in open land.


Evening primroses are adapted specialists, who above all grow in barren locations. In most cases additional fertilization is not necessary. If it grows as pot or container culture, then two to four weeks before flowering, gentle doses should be given with a commercially available herbal fertilizer. The liquid fertilizer is then simply added to the irrigation water.


As a wild herb, it tolerates dry periods in the wastelands for a long time. If it grows outdoors, then usually the normal rain cycles are sufficient. For longer lasting hot phases, should be poured vigorously in the evening. However, waterlogging should be avoided at all costs as otherwise the roots of the evening primrose will be damaged. Potted crops should be poured more often, because the mostly sandy soil can store little water.

Pests and diseases

Although the common evening primrose is quite undemanding, it is occasionally haunted by pests. Notably common pests are the downy mildew, the evening primrose bug or the infestation of Septoria fungi. The latter are noticeable by a greyish-red surface. Fungal infestation is often caused by small planting distances or frequent watering. Infested plants can be treated with herb broths made of common horsetail or stinging nettles. In case of infestation with Septoria the infected plants should be removed, since the fungi usually spreads quite quickly.


Most plants are biennial. After the first year, no special wintering is necessary, as the evening primrose is very frost tolerant. The leaves shoot out of the rhizome in the following year and continue to grow normally. In very cold winters, the plant may be covered with leaves or brushwood.

Flower of Evening Primrose
Flower of Evening Primrose

Evening primrose and its use

As a kitchen herb

In the past, the evening primrose was also called ham root. The name comes from the one hand, that the roots turn reddish when cooking. On the other hand, because the roots probably contain a lot of nutrients. An old saying from the early modern period, for example, says: One pound of the evening primrose gives more strength than a hundredweight of oxen. This saying and other older lore suggest that the herb was not an unknown plant in the kitchens.

Evening primrose is one of the edible and healthy wild herbs. Can be used:

  • Leaves (before flowering)
  • Roots (after flowering)
  • Stem (edible, but not a taste highlight)
  • blossoms
  • Seeds (very protein and oil rich)

Many wild herb enthusiast appreciate the numerous varieties of flavor the evening primrose offers. The root is said to be very similar in taste to black salsify and can be prepared just like this. The leaves, however, have a slightly spicy and slightly tart taste, reminiscent of a blend of chard and spinach. The leaves can be cooked as a vegetable or prepared raw.

An interesting dish are evening primrose leaves in combination with fried potatoes and venison. Also, simple dishes such as potatoes, cooked evening primrose leaves and scrambled eggs can be delicious. When using the leaves, however, care should always be taken that the harvest takes place before flowering, otherwise the leaves become more bitter. The stem leaves are generally tastier than the bottom leaves.

The flowers can also be used They smell pleasant and develop a slightly sweet taste. You can among others use them for garnishing salads or desserts. The flower buds, for example, can be fried with a tasteless oil.

As a medicinal herb

The common evening primrose (Oenothera biennis) is considered today in the naturopathy as a very valuable medicinal plant. Especially the seeds of the plant are of particular interest.

In older herbal books, there is no record of the use of this herb, which is quite simply justified by the fact that the herb found its way to Europe not until the 17th century. Even in the last century, there were only a few administration recommendations in folk medicine. There are, however, tribal knowledge that the Native Americans have given a bigger role to the evening primrose. For example, it is known that the seeds have been eaten frequently to strengthen the body in general.

For the naturopathy, today, especially the seeds are of particular importance. This is primarily because they contain high levels of gamma-linolenic acids and linoleic acids. Both acids are among the essential fatty acids that our body needs and can not produce itself. Especially the gamma-linolenic acid is medically interesting because it is able to assist in the production of so-called prostaglandins. In the body, the prostaglandins are mainly responsible for the development and regeneration of tissues as well as for fat metabolism. In addition, they are able to improve blood circulation and protect mucous membranes.

In summary, the evening primrose is among others used for the following complaints:

  • diarrhea
  • Strengthening the immune system
  • Skin complaints, e.g. itchy or scaly skin
  • eczema
  • neurodermatitis
  • Premenstrual syndrome (PMS)
  • Rheumatism / Rheumatoid Arthritis

The main administration is the treatment of various skin conditions. This is mainly because the ingredients contained in the seeds have an anti-inflammatory and antipruritic effect. An immune-enhancing effect was also observed. In particular, this is due to the fact that gamma-linolenic acid is able to support the production of white blood cells.

Among other herbs such as marigold, comfrey or borage, the evening primrose is one of the best medicinal herbs for skin complaints. Among other things, evening primrose oil is used for complaints such as dry skin (sebostasis), which is frequently observed in people with fair skin, poor perspiration or neurodermatitis. The fatty acids contained in evening primrose oil stimulate sweat production and give the skin moisture and elasticity. The oil can be mixed with other untreated cosmetic products such as shea butter or marigold ointment. Even herbal baths can provide significant relief when evening primrose oil is added.

Relatively new is the use of evening primrose products for the treatment of premenstrual syndrome. This fairly common disorder occurs in middle-aged women and manifests itself, among others, in tiredness, abdominal pain, mucosal irritations, diarrhea and skin complaints. It is reported that the intake of higher amounts of gamma-linolenic acids over a period of up to twelve weeks leads to a significant improvement in the symptoms. In contrast, however, there are studies that did not mention any significant improvement. However, it is not possible to check over which period of time the preparations were taken. In naturopathy, evening primrose capsules with higher levels of gamma-linolenic acid are recommended for the treatment of PMS.

Side effects:

Side effects are currently unlikely if properly taken. However, people with schizophrenia and epileptics should avoid the evening primrose or consult their doctor. Pregnant women and nursing mothers should discuss the oral intake of evening primrose products with a doctor or pharmacist, as the research situation here can not be sufficiently discussed. The overdose may cause nausea.

pink evening primrose
pink evening primrose

Buy Evening Primrose – What to pay attention to?

Since the health benefits of evening primrose have been described in many media, the demand for cosmetic products and food supplements with evening primrose oil has increased significantly. The oil itself is experiencing a large sales, which is sometimes reflected in the price.

When purchasing cosmetic products with evening primrose oil, care should be taken to ensure that all other ingredients are of natural origin. Especially if creams or ointments are used in the treatment of dry skin or neurodermatitis. Sometimes emulsifiers or surfactants are used as base, which generally dry out the skin. These surfactants and additional perfumes should be avoided.

For pure skin care, but also for direct oral intake, pure evening primrose oil is also recommended. The prices for 100 ml (3.5 fl oz) are often between 6 and 14 EUR/$, depending on the method of cultivation of the oil has been produced. When buying evening primrose oil, you should make sure that the oils are always cold pressed.

Capsules with evening primrose oil can provide relief especially for (atopic) eczema. Many reviews on online marketplaces are quite positive. Since the dosage is predetermined, capsules are usually cheaper than pure evening primrose oil, which should be used more for acute skin problems.

For gardeners, who want to grow the common evening primrose in their garden, there are online market places dealers, which offer a large quantity of seeds at favorable prices. However, many well-known seed producers only keep different types of this plant, as the common evening primrose is usually ill-reputed as weeds. When buying seeds or young plants you should therefore pay attention to the botanical name Oenothera biennis.

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