Pink evening primrose

Sun

Full sun; tolerates light shade but flowers less and may become floppy.

Water

Water regularly during establishment; once rooted, water during prolonged drought. Avoid persistently wet soil.

Soil

Well-drained sandy, gravelly or loamy soil; tolerates poor soil and a broad pH range. Avoid heavy, waterlogged ground.

Height

1-2 ft (0.3-0.6 m)

Spread

1-2 ft (0.3-0.6 m) initially; running roots can form much wider colonies.

Flowers

Late spring through summer, sometimes repeating into autumn; white to rose-pink flowers with yellow centres and darker pink veins, often becoming pinker with age.

Foliage

Narrow to lance-shaped green leaves, sometimes toothed or shallowly lobed; usually dies back in winter and may thin out during severe summer drought.

Growth

Fast, especially in warm weather with available moisture.

Care needed

Medium

• Water newly planted clumps whenever the surrounding soil begins to dry; reduce watering once established.
• Do not routinely feed; rich soil and excess fertiliser encourage sprawling growth.
• Keep winter mulch light and away from the crown, particularly on moisture-retentive soil.
• Remove unwanted runners promptly, digging out the connecting roots rather than only pulling the shoots.
• Divide crowded clumps in spring and replant only what you can accommodate.

Pruning. After the main flush of flowers, shear back straggly stems to encourage fresh growth and possible repeat flowering. Cut dead stems to ground level in late winter or early spring.

Early spring

Cut away dead stems and check for runners spreading beyond the planting area.

Spring

Plant or divide into well-drained soil, then water thoroughly.

Late spring

Check nearby plants for encroaching shoots and dig out unwanted roots.

Summer

Shear lightly after the main flowering flush; water established plants only during prolonged dry spells.

Autumn

Remove seed capsules if you want to limit self-seeding.

Winter

Keep crowns free of wet leaves and avoid watering dormant plants unless the soil is unusually dry.

• Use as a flowering groundcover on a sunny, well-drained bank where it has room to spread.
• Plant in a large gravel bed with yarrow and ornamental grasses for a loose, drought-tolerant planting.
• Let it soften the edge of a broad path, keeping it away from small plants that its runners could overwhelm.
• Combine with catmint and salvias for a pink, blue and violet cottage-garden planting.
• Grow in a large container where its roots are easier to contain.

Garden styles it suits: Cottage garden, Wildflower, Pollinator garden, Dry gravel garden, Pastel border and Desert / xeriscape.

Plant it with: Catmint, Yarrow, Meadow sage, Lavender, Little bluestem and Blanket flower.

Wildlife: Flowers provide pollen and nectar for bees and other visiting insects. Caterpillars of some moths feed on evening primroses.

• Unwanted spread: dig out runners with their roots and inspect the edges regularly; use a container where containment matters.
• Root or crown rot in wet soil: improve drainage or move the plant to raised, freely draining ground.
• Floppy stems and poor flowering: provide more sun and stop feeding with nitrogen-rich fertiliser.
• Leaf spots or powdery mildew: improve airflow, water at soil level and remove badly affected foliage.

Not known to be toxic to people, cats, dogs or horses. No particular plant part is recognised as poisonous, but it is not a recommended food plant; eating substantial amounts of garden foliage may cause digestive upset.

Where it spreads. Can spread aggressively by running roots and seed, particularly in the southern and western United States and in warm Australian gardens. Its behaviour varies with climate and soil; keep it out of natural areas and check local invasive-plant guidance before planting.

• Siskiyou evening primrose (Oenothera rosea)

  Usually has much smaller, deeper rose-pink flowers and a more upright, branching habit rather than broad drifts of large, pale cups.

• White evening primrose (Oenothera albicaulis)

  An annual with upright stems and flowers that open white and age pink; pink evening primrose is perennial and forms colonies through spreading roots.

• Missouri evening primrose (Oenothera macrocarpa)

  Has large yellow flowers, a low trailing habit and conspicuously winged seed capsules, rather than pink or white flowers.

The species name speciosa means showy, referring to its conspicuous flowers.

Propagation. Divide rooted sections in spring or take basal cuttings. Sow seed in spring; seedlings may vary in flower colour, and named cultivars should be propagated vegetatively to retain their characteristics.

Accepted botanical name

Oenothera speciosa

In the US and Canada

Native in the lower 48 states.

Native range

Arkansas, Indiana, Iowa, Kansas, Louisiana, Mexico Central, Mexico Northeast, Mexico Northwest, Missouri, Nebraska, New Mexico and Oklahoma.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.