How to Grow Lamarckiana
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Lamarckiana
Oenothera lamarckiana
flowerOenothera lamarckiana, commonly known as the Large Evening Primrose or Lamarck's Evening Primrose, is a biennial or short-lived perennial native to Mexico. It produces tall spikes of large, fragrant yellow flowers that open in the evening and close by morning. This plant is historically significant in genetics, having been the subject of Hugo de Vries' famous mutation studies.
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Example Lamarckiana timeline · Pittsburgh, PA (Zone 6b)
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Plant Lamarckiana
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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First Lamarckiana blooms
Mid-to-late summerBefore the first fall frost (≈ Nov 8)
Sample dates for Pittsburgh, PA. Sign up to get exact Lamarckiana dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 5-9, tolerates zone 4 with winter protection
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Germination & Seedling
7-14 days to germination; 3-4 weeks to true leavesTiny seedlings emerge with small oval cotyledons. Plant requires light for germination, so seeds should be barely covered or surface-sown.
Keep soil consistently moist but not waterlogged. Provide bright light. Thin seedlings to proper spacing when 2-3 inches tall.
Vegetative Growth (Year 1)
6-9 monthsPlant develops a rosette of long, narrow, lanceolate leaves with slightly toothed margins. Foliage is typically gray-green. Minimal above-ground growth in first year as energy is invested in root development.
Water moderately; allow some drying between waterings to encourage drought tolerance. Avoid fertilizing; lean soil actually improves flowering. Remove any flower buds that appear to strengthen plant.
Bolting & Flowering (Year 2)
8-12 weeks of active floweringPlant sends up a tall, unbranched or sparsely branched stem reaching 3-5 feet tall. Large, bright yellow flowers (1.5-2 inches across) appear in succession along the stem. Flowers are fragrant and nocturnal, opening in late afternoon/evening.
Provide support stakes if in windy locations. Deadhead spent flowers to encourage continued blooming. Water during dry spells but avoid excessive watering. Flowering may continue for 2-3 months.
Seed Production & Senescence
6-8 weeksFlowers fade and are replaced by elongated seed capsules. Plant gradually weakens and foliage yellows. Seeds mature within papery capsules.
Allow some flowers to mature into seed pods if you want self-seeding. Deadhead others to extend blooming. Stop watering as plant enters dormancy.
Dormancy/End of Cycle
Varies by climate; dormancy through winter in cold zonesPlant dies back completely after frost in cold climates, or may persist as a weak perennial in warm zones. Seeds are released when capsules dry and split.
Collect seed pods before they split completely if you want to save seeds. Allow fallen seeds to self-sow, or clear debris to prevent excessive self-seeding. In zones 8-9, plant may weakly resprout.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Hand-pick affected flowers and buds. Use insecticidal soap for severe infestations. Encourage natural predators like birds and parasitic wasps.
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Spray with water to dislodge. Use neem oil or insecticidal soap in warm, dry conditions. Increase humidity around plant base.
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Spray with water to remove. Apply insecticidal soap or neem oil. Encourage beneficial insects like ladybugs and lacewings.
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Hand-pick in early morning. Create barriers with copper tape or diatomaceous earth. Set beer traps nearby.
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Improve drainage immediately; reduce watering. Repot in fresh, sterile soil. Remove severely affected plants. Avoid overhead watering.
Uses
Evening-Blooming Cut Flowers
CulinaryThe large, fragrant yellow flowers are excellent for evening flower arrangements and night-blooming displays. Cut stems in late afternoon for overnight enjoyment. [source]
Traditional Herbal Remedy
MedicinalEvening primrose species have been used traditionally in herbalism for various purposes, though Lamarckiana specifically has limited modern medicinal documentation compared to common evening primrose oil species. [source]
Ornamental Garden Specimen
HouseholdValued for its tall, dramatic vertical accent and prolific flowering in cottage gardens, wildflower gardens, and dry sunny borders. Creates striking evening displays. [source]
Historical & Scientific Interest
CraftFamous for its role in Hugo de Vries' mutation experiments and the development of modern genetics; grows well in botanical gardens and educational settings demonstrating evolution. [source]
Night-Flying Pollinator Support
WildlifeThe nocturnal flowers attract moths, night-flying insects, and some bat species. Provides important nectar source for evening pollinators. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Flowers can be cut in late afternoon just before they open for evening arrangements; they will open indoors. For seed collection, allow flowers to mature into seed pods. Harvest seed capsules when brown and papery but before they split. Store dry seeds in a cool, dry place. Seeds have high germination rates for 2-3 years.
Fun Facts
- 🌱 Oenothera lamarckiana was the primary plant species used by Dutch botanist Hugo de Vries in the early 1900s to demonstrate the mutation theory of evolution, earning it a place in the history of genetic science.
- 🌱 The flowers are distinctly nocturnal, opening in the early evening (typically around 5-7 PM) and closing by morning, a strategy to attract nocturnal pollinators like moths and hawk moths.
- 🌱 Despite being called 'Evening Primrose,' Oenothera is not a primrose at all but belongs to the Onagraceae (evening primrose) family; true primroses belong to the Primulaceae family.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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