Evening Primrose
Oenothera biennis
flowerEvening primrose (Oenothera biennis) is a native biennial famous for its show at dusk: large, fragrant, lemon-yellow four-petaled flowers that unfurl in the evening, sometimes visibly, to be pollinated by night-flying moths, then fade by the next midday. In its first year it makes a flat rosette; in its second it sends up a 3 to 5 ft flower stalk that blooms for weeks. Nearly the whole plant is edible - the first-year root is boiled like a vegetable, the young leaves and flowers go into salads - and the oil-rich seeds are the source of the well-known evening primrose oil. Tough and self-sowing, it thrives in poor, dry ground.
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Sun
full sun
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Water
Every 8 days
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Bloom
~120 days
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Difficulty
easy
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Lifecycle
biennial
Leaves year 1, flowers year 2
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Spacing
12 in. apart
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Planting Depth
Surface sow; needs light
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Soil pH
5.5-7.0
Growing Details
Soil Type
Average to poor, well-draining
Hardiness Zones
Zones 4 – 9
Grown as an annual. This range is its winter hardiness, but you can grow it for a single season in any zone.
When to Fertilize
None to light
Fertilizer
None; prefers lean soil
🌱 Growing Guide
Evening primrose is easy in average to poor, well-drained soil in full sun - it actually prefers lean ground and tolerates drought, growing leggy in rich soil. Sow seed on the surface (it needs light) in late summer or early spring where it is to grow, as it resents transplanting, and thin to about 12 in. apart. Water to establish, then little is needed. As a biennial it makes a rosette the first year and flowers and seeds the second, then dies, but it self-sows so freely that a patch renews itself indefinitely; deadhead the seed stalks if you want to limit its spread.
🌼 Have a different variety?Cultivars of the same species usually share the same basic care, and they differ mainly in flower color, height, and bloom form, not in how you grow them. So this guide still applies even if your exact variety isn't the one shown.
Planting Calendar
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Direct sow
Apr 29
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Projected first bloom
Aug 27
JJan
FFeb
MMar
AApr
MMay
JJun
JJul
AAug
SSep
OOct
NNov
DDec
✅ Plant alongside
Good neighbors that attract beneficial insects or deter pests
- Yarrow: A fellow tough, drought-hardy plant for a lean, sunny wildflower bed that feeds pollinators
- Purple Coneflower: Shares the same easy, sunny conditions and extends the pollinator season
- Cosmos: An airy annual that mingles in a low-care, self-sowing flower patch
🛡️ Pest & disease prevention
Proactive ways to stop trouble before it starts. Tap a name with an arrow for its full guide
Hose colonies from the stems; predators usually follow outdoors
Hand-pick in the cool morning; they may chew the flowers and leaves
Give sun and airflow and avoid crowding in humid late summers
🌸 Blooms & cutting
Dig the first-year root in fall or early the following spring, before the plant bolts, to boil or roast like a vegetable. Pick the young leaves and the flowers in season for salads. For the seeds, let the flower stalk finish and the seed pods turn brown and dry on the plant, then cut the stalks and shake out the tiny seeds. Gather flowers and leaves young and tender, as both toughen with age.
🥗 Nutrition & benefits
Evening primrose is widely edible: the first-year root is a starchy boiled vegetable, the young leaves and fragrant yellow flowers go into salads, and the seeds are pressed for the well-known evening primrose oil, rich in gamma-linolenic acid. It is grown as much for its dusk-opening, moth-pollinated flowers and its value to wildlife as for the kitchen.
For educational and informational purposes only. HomeSown is not medical, health, or other professional advice. Always positively identify any plant before handling or eating it; some plants, and some parts of otherwise-edible plants, are toxic. Consult a qualified professional before consuming or otherwise using any plant, especially if you are pregnant, nursing, taking medication, or have a health condition.