Evening Primrose (Oenothera biennis) is a hardy biennial or short-lived perennial wildflower known for its striking yellow blooms that open in the evening and stay open overnight. This charming plant adds a splash of colour to Irish gardens from late spring through summer and is a magnet for moths and night-time pollinators.

Thriving in full sun and well-drained soils, Evening Primrose is tolerant of poorer soil conditions and drought once established. It is ideal for wildflower meadows, cottage gardens, and pollinator-friendly landscapes.

Horticultural Points

• Botanical Name: Oenothera biennis
• Type: Biennial / short-lived perennial
• Height: 60–120 cm (24–48 inches)
• Bloom Time (Ireland): June to September
• Flower Colour: Bright yellow
• Position: Full sun preferred
• Soil Requirements: Well-drained soil, tolerates poor soils
• Spacing: 30–45 cm apart

Growing Information (Ireland)

• Sow seeds directly outdoors in spring or autumn.
• Prefers a sunny, sheltered location.
• Self-seeds readily, making it great for naturalised planting.

Note on Irish Climate Suitability

• Evening Primrose thrives in Ireland’s temperate climate and is well adapted to local soil and weather conditions.
• Its evening blooms provide unique garden interest and support nocturnal pollinators.

Historical Background

• Native to North America, Evening Primrose has been embraced in European gardens for its beauty and ecological benefits.

Ecological Note

• Its oil-rich seeds have been used traditionally for medicinal purposes, and it remains a valuable plant for biodiversity.