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.
Growing Evening Primrose
Evening Primrose | Genus: Oenothera
Evening Primrose Growing Guide
Herbaceous flowering plant
• Hardiness zones 3 to 9
• Full sun – at least 6 total hours of direct sun per day
• Light loam or sandy soil
• Some Oenothera flowers open just in evening, evolving with specific evening pollinators.
• Check your specific variety for any known aggressive reseeding or spreading.
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).
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.
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).
Yes, some evening primrose is invasive or aggressive in some areas. There are both perennial and annual varieties. Before planting, check what is native or non-native in your region.
Here in southwestern Ontario, Canada, I find the roots require division each year as they expand rapidly. I also cut the plants back after flowering to stop them from producing and sowing seeds. Thankfully, it is easy to reduce or remove.
Yes, you can grow evening primrose in containers. I think you can grow just about anything in a container so long as you have adequate root space, good potting mix, provide light and water as needed, and have suitable winter storage.
I keep various perennials in containers and put them in the shed or garage from fall to spring. A hand cart / hand truck makes it much easier to move them around.
Animals reliant on evening primrose include Schinia felicita and S. florida moths that feed exclusively on the Oenothera genus.
Pollination is provided by various moths, bees, and insects, although the structure of the flower limits the number of capable pollinators.
Some evening primrose open their flowers in the evening and are therefore used by nocturnal pollinators like moths.
It’s not necessary to prune evening primrose for basic plant health but perennial varieties can be cut back after blooming to prevent the forming of seeds if you don’t want them self-seeding.
Find Your Frost Dates & Hardiness Zone
Average Frost Dates | Use this calculator at Almanac.com. Enter your city and state or province to find your first and last frost dates and number of frost-free days.
Ecoregion | Learn about the native plant and animal species and environmental conditions specific to your region to better understand why your garden choices matter.
Learn More: Understanding Frosts & Freezing For Gardeners
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~Melissa the Empress of Dirt ♛
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