How to Grow Oenothera Plants

Guide to Growing Pink Ladies, Suncups, Pink Ladies, White Buttercups and Sundrops

The Oenothera is a large genus that contains 145 herbaceous plant species, these can range in height from 15 to 90 cm (6 inches to 3 feet).

They can be annual, biennial, or perennial in nature, but are normally treated as an annual by gardeners.

Oenothera pallida
Oenothera pallida - Pale Evening Primrose by Matt Lavin; Creative Commons.

They bloom for a short period in spring or summer (species dependent) with cup shaped flowers; these can be pink, white or yellow.

Oenothera perennis
Oenothera perennis - Small Sundrops by Gmayfield10.

Some of the common names for Oenothera include Evening Primrose, Sundrops, and Desert Evening Primrose.

Commonly Grown Oenothera Species

Oenothera biennis

Oenothera biennis
Oenothera biennis (Common evening-primrose), photograph by Andreas Rockstein; CC.

Oenothera speciosa

Oenothera speciosa
Oenothera speciosa (Pink evening primrose), picture by Leonora (Ellie) Enking; CC.

Oenothera Growing and Care Guide

Common Names: Evening Primrose, Suncups, Sundrops, Pink Ladies, White Buttercups.
Life Cycle: Hardy annual. Hardy biennial. Hardy perennial commonly grown as a hardy annual by gardeners.
Height: 4 to 120 inches (10 to 300 cm).
Native: Americas.
Growing Region: Zones 4 to 9.

Flowers: Spring and summer.
Flower Details: Yellow, white, pink, orange. Cup-shaped.
Foliage: Basal rosette. Dentate. Deep lobes.
Sow Outside: Cover seed. Start of spring or in autumn (warm areas). Spacing 4 to 40 inches (10 to 100 cm).
Sow Inside: Use peat pots. Germination time: one week to one month. Temperature 70°F (21°C). Nine or ten weeks before expected last frost. Transplant outdoors following the last frost.

Requirements: Full sunlight or light shade. Good drainage. Soil pH 5.5 to 7. Sandy soil. Light soils. Can survive in dry soils.
Provide support. Provide trellis. Occasional feed.
In the spring supply a top dressing of cow manure.
Prune once flowering has completed.
Propagate: dividing cuttings in the spring. Divide in the autumn in warm areas or in spring elsewhere.

Family: Onagraceae.
Miscellaneous: Invasive plant in many areas. Has many culinary and medical uses: young roots are used as a vegetable; shoots in salads; and the seeds are used to produce evening primrose oil, a commonly used health supplement.

How to Grow Evening Primrose and other Oenothera Plants

The seeds of Evening primrose can be sown outdoors just before the last frost of spring or in autumn in warm areas.

Once sown lightly cover the evening primrose seeds. Oenothera species are able to grow in either partially shaded or sunny parts of the garden.

They are partial to a light soil that is a little sandy and slightly acidic (pH 5.5 to 7).

Oenothera plants can be grown indoors first. They should be germinated in the dark at 18 to 20 degrees centigrade (64 to 68°F), about ten weeks in advance.

Plants should take around one to four weeks to germinate. Once ready transplant into the garden following the last frost. Oenothera should be spaced at 15 cm (small) to 50 cm (large) apart (6 to 20 inches).

Caring for Oenothera

Once growing it is fairly easy to take care of Oenothera genus plants.

They should be watered during dry months, and pruned back following flowering to prevent them from producing seeds; as they can take over the garden.

It is best to supply Oenothera with manure in the spring. If you require more plants then they can be propagated by taking cutting in the spring.

Common Questions

How many members does the Oenothera genus contain?

The Oenothera genus contains about 145 species. These plants, also known as Evening primroses.

Do Oenothera members make a good garden or landscaping plant?

Yes, Oenothera make excellent garden plants. Their beautiful, large flowers can brighten up any garden, and some species are perfect for rockeries or borders.

Which Oenothera species are most frequently grown by gardeners?

Oenothera biennis (Common Evening Primrose) and Oenothera missouriensis (Missouri Evening Primrose) are popular choices due to their attractive flowers.

Are Oenothera plants fragrant?

Many Oenothera species release a gentle, sweet fragrance, particularly in the evenings or at night to attract pollinators.

What is the perfect location to grow Oenothera?

Oenothera plants do well in full sun with well-drained soil. They are drought-tolerant, making them suitable for xeriscaping or low-water gardens.

Is Oenothera invasive in the USA, if so in which states?

While Oenothera can spread through self-seeding, they are not considered invasive in the USA. Gardeners should monitor their growth to prevent unwanted spreading.

How do I remove Oenothera plants from my garden?

Removing Oenothera involves digging up the plants, taking care to get the entire root system. Regular removal of spent flowers can help prevent self-seeding.


Oenothera is a genus of the Onagraceae family, often referred to as Evening primroses. These annual or perennial plants are admired for their charming, usually yellow flowers that often open in the evening, hence the common name.

Plant Oenothera in a sunny spot with well-drained soil. Sowing is typically done in spring. With their unique blooming habit and attractive form, they make great additions to borders, rock gardens, or even as a ground cover, providing beautiful color from late spring to late summer.

I hope that you enjoyed this guide on how to grow Oenothera plants. You may also enjoy the following Gardener's HQ growing guides: How to grow Gaura and Zauschneria plants.