All About Evening Primrose

Lindsay Gray talks us through all you need to know about evening primrose – including how to make the oil

Oenothera biennis or evening primrose as it is commonly known, is a pretty perennial that has been around for centuries. Native to North America, it found its way to Europe in the 1600s and has naturally been taken to many other countries. It is called ‘evening’ primrose because the flowers open in the early evening and might last until noon the next day before fading.

It can be classed as an annual, biennial or perennial, depending on the variety. Some have an upright growth while others are low-growing and more suitable as a groundcover. In South Africa we mostly grow the yellow Oenothera that has an upright growth. While not bushy, its branching habit does require some space, so allow for at least 400 – 500mm per plant as it matures.

Medicinal properties

We are familiar with evening primrose as a pressed oil that is marketed in capsule form, largely to treat rheumatoid arthritis, certain skin conditions and osteoporosis. The gamma-linolenic acid contained within the oil – a type of omega-6 fatty acid – is used by the body to regulate blood pressure and to keep the immune system functioning well, for mood stability during menopause and it has been found to vastly improve depression in some patients.

Native Americans used the whole plant for treating bruises, a poultice of the leaves to treat minor wounds, gastrointestinal issues and sore throats, while the roots were used for treating haemorrhoids.

As a plant however, one might eat the root with its light, peppery flavour or make an infusion of the flower for topical use. The new leaves and yellow flowers can be used in salads.

How to grow

This pretty plant loves full sun and is easy to grow, requiring regular watering when you first plant it or when you notice seedlings appearing, as the plant self-seeds in late winter/early spring. Thereafter leave it to the summer rainfall. If you grow this plant in a winter rainfall area, then it is best to water it weekly during the dry summer months so that you can harvest a good crop of flowers and seeds.

The plant will enjoy the same well-composted soil as do your other plants with additional watering in the dry months. It is best grown in cooler climates and is not suited to humid coastal areas.

I was gifted some evening primrose seedlings at the beginning of summer last year. They responded to their new home immediately, producing long stems covered in pretty, yellow flowers to about 500mm in height, whereas in cold climates, they sometimes only flower in their second year.

Even as the plant started to set seed, the flowers continued. I seemed to miss the right time to collect the seed but that could be because the birds had got there before me, however I now have about fifty new seedlings popping up just adjacent to the original planting. I will wait a few weeks, then lift them and either plant them elsewhere in my garden or pot them up to give to friends.

If you prefer to sow seed, then collect them early and, depending on how cold your winter is, either sow them immediately on top of the soil and water well, or store and sow them when the weather starts to warm.

Gardening with evening primrose

Treat this delightful perennial as you would any other sun-loving perennial and combine it in a flower border with daylilies, agapanthus, irises, tulbaghia, salvia and even indigenous grasses.

Pollinators love the flowers of this pretty plant while seed-eating birds enjoy snacking on the seeds when the capsules burst open. You will be rewarded with the perfect show of yellow all summer!

Disclaimer: before using any plant for medicinal use, please consult your doctor.

Making your own evening primrose oil

Fill a jar with fresh flowers and cover them completely with a carrier oil of your choice – olive and grape seed oil is suitable. Press the flowers down to ensure that no air is trapped in the oil and then let it sit in the oil for at least two weeks, shaking the jar lightly every day. It is advisable to use this homemade oil for topical applications only to the skin and hair.

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