Evening Primrose
The Evening Primrose’s are generally known for flowers that close during daylight hours; the flowers are therefore hermaphrodite, produced on a tall spike and only last until the following noon. They open visibly fast every evening producing an interesting spectacle, hence the name “evening primrose.” Good to start in the spring.
Botanical Name: Oenothera biennis
Nom Français: Onagre bisannuelle.

The Basics

Bloom colour: Yellow
Blooms: Summer - Zone 5
Pollinators: Birds
Sun or Shade: Full Sun
Plant Type: Perennial
Height: Up to 5 feet (160 cms)
North America
It grows well in hardiness zones: 4 - 8

This lemon-scented flower is perfect for moon gardens as it blooms in the evening. Although it is a night bloomer, it still requires at least 6 to 8 hours of sunlight per day.

Planting

Rocky or sandy soils.
Water requirement: Low, Average.
Well-drained soil and can tolerate high pH levels.
Primrose is self seeding, so it has a tendency to spread and may take over your garden if not maintained. It is considered a weed to some due to its invasiveness. Consider using a thick layer of mulch to keep its roots cool. If you notice its leaves are brownish, this may mean it has been over watered and might be suffering from root rot. This plant prefers cooler temperatures, so plant in early spring to reduce the chances of the plant becoming leggy or weed-like. Fertilizer is not needed.
You can obtain seeds directly from the flower, but if you buy seeds, plant them in late autumn or early spring. Ensure they have plenty of sunlight. Spread the seeds on top of the soil and water well. After germination thin out the seedlings so they are approximately one foot apart.

Care

Easily grown in average, medium moisture, well-drained soils in full sun. Grows well in gravelly or sandy soils. May spread in the landscape by self-seeding in a somewhat weedy fashion. Transplanting an evening primrose plant will probably not succeed, so you are better off planting them from seed.
Does well in newly established landscapes, but does not persist. Spread seeds will germinate if soil is disturbed.
You can expect to see various traditional garden pests, including mealybugs, spider mites, and aphids. If you notice signs of infection, treat them with insecticidal soap or neem oil.

Pruning

Spread: 60 to 90 cm
Primrose will not flower in its first year of planting. In year two, a tall flower stem appears and thin, secondary branching occurs. The blooms will grow to about 1 inch wide and they'll eventually die off and produce seeds that will spread throughout the landscape or be eaten by birds.

Considerations

The oil from the seed is added to skin preparations and cosmetics. It is often combined with vitamin E to prevent oxidation. A yellow dye is obtained from the flowers. A finely ground powder made from the flowering stems is used cosmetically in face-masks to counteract reddened skins. It can also be used to treat asthma, migraines, eczema, inflamation, PMS, high cholesterol and more.
Edible

Styling and Use

It attracts a variety of moths, small mammals, birds (including hummingbirds), deer and nocturnal bees and it thrives in sandy or rocky soils. Biennial, it is appropriate for beds and borders, wildflower, cottage gardens and herb gardens.
Consider harmonizing colors and bloom forms of daylilies and heleniums.

Other

Evening primrose can help with a variety of skin conditions such as acne and it may also promote hair growth. The flowers are also edible raw or cooked, and are sometimes used in salads.

History

Both First Nations and settlers used evening-primrose for several medicinal purposes. They treated wounds and bruises with a poultice of leaves, while a tea or infusion of the plant was drunk to soothe coughs and digestive complaints.

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