Evening Primrose
Scientific Classification & Quick Facts
| Common name | Evening primrose |
| Scientific name | Oenothera biennis |
| Kingdom | Plantae |
| Phylum | Tracheophyta |
| Class | Magnoliopsida |
| Order | Myrtales |
| Family | Onagraceae |
| Genus | Oenothera |
| Type | Biennial herb |
| Habitat | Sandy, disturbed ground in full sun |
| Lifespan | About 2 years |
| Colours | Yellow, lemon-scented flowers |
| Flowering season | June to October |
| Edible parts | Leaves, roots and flower buds |
| Special feature | Flowers open in the evening; hawk moths pollinate |
Evening Primrose which is technically called Oenothera is a member of the Onagraceae family. It is native to eastern North America and is now found in many parts of the world. This herbaceous flowering herb has altogether 145 types of species, but they are not similar or related to the genus Primula which is commonly known as True Primrose. The other names of this plant are sun cup and sun drop. As the name suggests, this plant blooms at night with beautiful and fragrant yellow flowers. It has been used in traditional herbal medicine. All the parts of the plant are edible. The leaves can be consumed like spinach and the roots can be used like potatoes.
History
It is believed that the evening primrose species are native to North and Central America; Oenothera biennis is generally considered native to eastern North America. But with the evolution of international travel, this plant spread to all parts of the world. Now it can be seen in all temperate zone areas. There are around seventy introduced species in Europe itself. Studies found that it was a staple food for Native Americans who ate its boiled roots and used the leaf poultices to apply to bruises. It is said that in those days, hunters used to rub the roots of this plant to the sole of their moccasins to mask their smell from the animals so as to get closer to them while hunting. Europe introduced this plant to England and Germany and it became a part of their food. It was known by the name German Ramp Ion. During the 17th century in England, this herb was known as the kings cure-all by herbalists, due to its ability to cure a wide variety of ailments. The botanical name of Oenothera comes from the Greek,Oinos which means wine and Ther which means wild animals. America was affected by ice age during the period of the Pleistocene era. The ice age, which intervened the warmer period, resulted into four different colonization waves which led to the formation of present day sub-division, Euoenothera.
Anatomy
Oenothera is a biennial plant which is often found along the banks of rivers and other sandy places. It has a life cycle of around 2 years. The stem is erect, stout and slightly hairy. The leaves are tapered and narrow and grow around 5 to 20 cm in length and 1 to 2.5 cm in breadth. During the first year, the leaves grow in a bunch or rosette whereas in the second year it can be seen spirally on the stem. The flowers are yellow in color and appear anytime from June to October. It grows about 2.5 to 5 cm in diameter and have 4 bilobed petals. The flowers of this species have an x shaped pistil that projects beyond the stamens. Flowers have a lemony scent and grow in spikes on auxiliary branches all along the stalk. It has a specific nectar guide arrangement which is invisible to our naked eye. This species undergo pollination by large hawk moths and hummingbirds.
Habitat
Common Oenothera, being a hardy plant can be seen almost in all counties of Illinois. It is found immensely during the end of summer or in autumn. It naturally develops or can be cultivated very well in disturbed areas. It prefers acidic, basic, neutral and well drained sandy soil. It can be seen on mesic soil prairies, sand prairies, waste areas, roadsides, lake shores, drainages, thickets, railroads, abandoned fields, drainage ditches, etc. It is effectively a wild plant. If once the plant is introduced and the seeds are allowed to scatter then it will grow very wildly.
Soil
Evening primrose prefers disturbed soils. It can grow in black soil prairies and mesic soil. Usually it grows well in acidic and alkaline soil. It can be seen in dry sites as well. As long as the soil is not too wet, Evening primrose will happily thrive in any soil.
Temperature and Humidity
This plant requires full sun. But as it is a hardy plant, it can bear freezing temperature.
Planting
Evening Primrose can be easily cultivated by using seeds, where it gets sufficient light as it helps the seeds to germinate soon. Hence it should be properly spread over the soil surface. Freezing as well as watering the seeds help them to germinate soon, by breaking the seed cover. Transplanting this herb is not very successful because the roots of this plant grow very deep into the soil, and so care should be taken while removing. This is a biennial plant and so it reseeds itself; hence, as soon as the flower stem fades, snap off the flowers so that it will prevent the seeds from ripening and spreading. The weeds around the plant should be regularly cleared as it wont allow the plant to grow. Seeds propagate within 15 to 30 days. During autumn, cold frames can be used to sow the seeds.
Watering
During the growing period, the base of the plant should always be damp. It should be watered frequently. Around 1.5 to 2 liters of water can be used to water the plant every two weeks. Especially when the weather is too dry and hot, watering should be regularly done.
Care
Oil extracted from the Evening Primrose is traditionally used on the skin for dryness and eczema.
Uses
The oil of this herb is mainly used for skin problems such as eczema, psoriasis and acne. People have also tried the oil for many other conditions, but there is little good evidence that it works. In the manufacturing sector, this oil is very useful in making soaps and cosmetic products. It is a rich source of essential fatty acid and can be included in our daily dietary supplements. The other parts of this plant are edible too. The leaves and the roots are boiled and consumed. The flower bud can be eaten raw. The flowers are also added to the salads.
Pests & Diseases
Though studies say that this plant can resist pests and diseases, but there are many cases reported where this plant has been affected from various insects, pests, fungi and bacteria pathogens that affect the roots and seeds as well.
Evening primrose FAQs
Why is it called evening primrose?
Its fragrant yellow flowers open in the evening and at night. It is not related to true primroses.
How long does an evening primrose live?
It is a biennial, so it lives about two years. In the first year it forms a rosette of leaves, and in the second year it grows a flowering stem.
Can you eat evening primrose?
Yes, all parts are said to be edible. The leaves and roots are boiled, the flower buds can be eaten raw, and the flowers go in salads.
What pollinates evening primrose?
Large hawk moths and hummingbirds pollinate the flowers. The flowers have patterns that people cannot see.
How do you grow evening primrose?
Scatter the seeds on the soil surface in a sunny spot, since light helps them sprout. Do not try to transplant it, because the roots grow deep.

Randi Jones is the owner and founder of the Nature Gift Store, an online retailer specializing in nature-themed gifts, educational science projects, live animal nature kits and real butterfly artwork. A biology graduate who fell in love with insects, she founded the company in 2001 to make active learning about nature fun, accessible and engaging for children and adults. Her store offers real butterfly frames, home and garden decor and educational live animal kits, including ant farms, worm farms, tadpoles, ladybugs and hermit crabs, and she runs a bug museum in Washington featuring live animals like Eddie the Iguana alongside other reptiles and insects.
