How to Grow Evening Primrose (Oenothera) and Possible Problems

There are numerous species in the evening primrose genus (Oenothera). Some go by the common name “evening primrose” while others are known as “sundrops.” Each can add a beautiful burst of color to the garden and benefit native wildlife including pollinators.

For more cottage-style plant options, also see growing tips for hollyhocks, lilac, and peonies.

---

Growing Evening Primrose

Evening primrose (Oenothera) is one of many flowering perennials in my own cottage-style garden.

It started with a single plant and over just a few years has spread quite assertively in the sandy soil.

But, unlike horrific invasive or aggressive plants that spread by root-runners deep in the soil, evening primrose is not hard to control.

If I want a wide swath of yellow, I leave it alone. If I want to reduce it, I both divide the plants and cut back the flowers after blooming (to prevent seeds from forming).

---

Contents

• Evening Primrose Species
• Oenothera Plant Facts & Growing Tips
• Frequently-Asked Questions
• Resources

---

Evening Primrose Species

There are quite a number of Oenothera varieties (145 species), with different shapes and colors (yellow, pink, white). I am very fond of the Oenothera fruticosa (“sundrops”) with bold, yellow cup-like flower petals and orange-red stamens. The flower buds also have a gorgeous deep red color which stands out in the spring garden.

Here in my sandy, very well-draining soil, they spread fairly rapidly, forming colonies throughout the garden beds. Every year or two I remove a bunch to keep them in check.

Which Oenothera are considered native will depend on your location.

Species Examples

These are all attractive to various specialist bees, hummingbirds, and moths and act as larval host plants (plants a species requires for survival) for various species of wood-nymphs, sphinx, and more.

• Evening Primrose (Oenothera biennis)
  • Biennial | Blooms mid-summer to fall

• Meadow Sundrops or Prairie Sundrops or Meadow Evening Primrose (Oenothera pilosella)
  • Herbaceous perennial, Carolinian species, spreads well | Blooms late spring to early summer
• Narrow Leaf Evening Primrose or Sundrops (Oenothera fruticosa)
  • Herbaceous perennial | Blooms summer to fall

Oenothera Plant Facts & Growing Tips

• Family | Onagraceae
• Genus | Oenothera (ee-no-THEE-ruh)
• Species | 145+ species
• Common names | Evening primrose, suncups, yellow sundrops, meadow sundrops…
• Origin | Mexico and Central America, parts of North America
• Types | There are annual, biennial, and perennial varieties
• USDA Hardiness Zones | 3 to 9
• Height | Most grow 12 to 36-inches tall but there are tall exceptions
• Spacing | 12 inches although some spread in tight colonies
• Light | Full sun or close to it
• Soil | Light loam or sand, well-draining
• Flower Times | summer – can deadhead or cut back to reduce self-seeding
• Colors | Yellow, pink, white
• Fertilizer | Not required
• Pollinators | bees, moths, other insects
• Larval Host Plant | several native insect species
• Propagation | Divide plants or sow seeds (spreads nicely on its own)
• Problems | Can be invasive or aggressive by seeds or spreading. Check before planting. May get powdery mildew or leaf spot.
• Trivia | Despite the common name evening primrose, they are not closely related to primroses (genus Primula). Many Oenothera flowers open in the evening, attracting vespertine bees that forage at that time of day. There are many claims that evening primrose oil (a fatty acid) is effective in cancer treatments, acne prevention, relief of menstrual symptoms, eczema relief, hastening child birth labor (and more).

Frequently-Asked Questions

Resources

Happy gardening! And be sure to sign up for the free newsletter.

~Melissa the Empress of Dirt ♛