How to Grow Nemesia and Sundrops

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Nemesia and Sundrops

Nemesia strumosa (Nemesia) and Oenothera species (Sundrops)

flower

This is a combination of two distinct ornamental flowering plants. Nemesia is a colorful, compact annual with snapdragon-like flowers in vibrant hues, thriving in cool-season gardens. Sundrops (Evening Primrose) are perennial or annual flowers with bright yellow, pink, or red blooms that often open in evening hours, offering extended seasonal color.

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Example Nemesia and Sundrops timeline · Pittsburgh, PA (Zone 6b)

Plant Nemesia and Sundrops
Around Apr 17

Near Pittsburgh's average last spring frost.
Tend & protect
Late spring–summer

Watering, feeding, and pest-watch reminders.
First Nemesia and Sundrops blooms
Around Jun 6

≈ 50 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Nemesia and Sundrops dates for your own zip code.

Growing Conditions

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Sun: Full sun to partial shade; Nemesia prefers afternoon shade in hot climates (4-6 hours direct sun); Sundrops need full sun (6-8 hours daily)

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Water: Nemesia: keep soil consistently moist but not waterlogged; prefers cooler, humid conditions. Sundrops: drought-tolerant once established; water moderately during growth, reduce in established plants to encourage hardiness

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Spacing: Nemesia: 12-15 inches apart; Sundrops: 18-24 inches apart inches

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Days to maturity: Nemesia: 50-70 days from seed to blooms; Sundrops: 60-90 days from seed, earlier with transplants

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Planting depth: Nemesia seed: surface sow or barely press into soil (light-dependent germination); Sundrops seed: sow 1/8 inch deep; transplants: plant at same depth as container

Soil

Type: Well-draining loamy soil with moderate fertility

pH: 6.0-7.5

Amendments:

Compost or aged manure for moisture retention (Nemesia) Perlite or sand for drainage (especially Sundrops) Avoid heavy clay; add organic matter to improve structure

Growing Zones

Find your zone →

Nemesia thrives in zones 6-9 (cooler areas); Sundrops in zones 4-10 depending on species

3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a

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Growth Stages

Seedling

2-3 weeks

Tiny true leaves emerge within 1-2 weeks. Plants are delicate and require consistent moisture and bright light.

Keep soil moist; provide grow lights or bright windowsill. Maintain 65-70°F for Nemesia, cooler for best results. Thin seedlings to proper spacing once true leaves appear.

Vegetative Growth

3-4 weeks

Bushy foliage develops with multiple sets of leaves. Nemesia grows compact; Sundrops develop deeper root systems and wider rosettes.

Pinch back Nemesia at 4-6 inches to encourage bushiness. Keep soil moist for Nemesia; reduce water for Sundrops. Provide cool conditions (60-70°F) for Nemesia flowering. Deadhead spent flowers to redirect energy.

Budding & Early Bloom

2-3 weeks

Flower buds appear along stems. Nemesia displays clustered flower spikes; Sundrops show prominent buds at branch tips.

Continue consistent watering for Nemesia. Begin light feeding with balanced or flower-promoting fertilizer every 2 weeks. Ensure adequate light. Remove any diseased foliage.

Full Bloom & Flowering

4-8 weeks (Nemesia); 6-10 weeks (Sundrops)

Nemesia produces abundant colorful snapdragon-like flowers in reds, pinks, oranges, yellows, and bi-colors. Sundrops display large, showy flowers in bright yellow, pink, or red.

Deadhead regularly to extend blooming (especially for Nemesia). Water regularly but moderately—avoid wetting flowers. Apply low-nitrogen fertilizer if blooming slows. Nemesia blooms best in cool weather; may slow in heat.

Decline & End of Season

Variable; frost kills Nemesia; Sundrops perennialize or self-seed

Nemesia flowers fade and plant may bolt or decline in summer heat. Sundrops continue flowering but set seed; perennial types prepare for dormancy.

Nemesia: cut back heavily for fall rebloom or replant. Sundrops: allow some seed to set for self-sowing; cut back perennial types after frost. Collect seed before winter if desired.

Companion Planting

Plan your garden →

Plant with:

Salvia Diascia Calibrachoa Bacopa Dusty Miller Gaura Penstemon Coreopsis Russian Sage Catmint

Avoid planting near:

Allelopathic plants that inhibit growth Dense shade-casting plants Overly vigorous spreaders that compete for nutrients (not critical but can crowd)

Common Pests

Spray with insecticidal soap or neem oil; blast with water to dislodge. Encourage beneficial insects like ladybugs.
Increase humidity with misting; spray with neem oil or miticide. Remove heavily infested leaves.
Use yellow sticky traps; spray with insecticidal soap or neem oil. Hose down regularly.
Improve air circulation; avoid wetting foliage. Apply sulfur dust or fungicide spray. More common on Nemesia in humid conditions.
Ensure well-draining soil; avoid overwatering, especially for Sundrops. Remove and discard affected plants. Sterilize pots.

Uses

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Edible Flower Garnish

Culinary

Both Nemesia and Sundrops flowers are edible and add vibrant color and mild flavor to salads, desserts, and cocktails. Ensure no pesticides have been applied before consuming. [source]

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Cut Flowers & Floral Arrangements

Household

Both plants produce excellent long-lasting cut flowers for bouquets and arrangements. Nemesia's compact clusters work well in mixed designs; Sundrops create dramatic focal points. [source]

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Traditional Herbal Use

Medicinal

Oenothera (Sundrops) species have been used traditionally in herbal medicine, with evening primrose oil from related species valued for anti-inflammatory properties, though scientific evidence is ongoing. [source]

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Pollinator Support

Wildlife

Both Nemesia and Sundrops attract bees, butterflies, and other pollinators, providing valuable nectar and pollen sources throughout the blooming season. [source]

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Pressed Flowers & Drying

Craft

The delicate Nemesia flowers and sturdy Sundrops blooms press beautifully for crafts, scrapbooking, bookmarks, and botanical art projects. Air-dry or press between parchment paper. [source]

This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.

Harvest Tips

These are ornamental flowers—harvest stems for cut flowers in early morning when stems are full of water. Cut just above a leaf node with clean shears. Deadhead spent flower clusters to encourage continuous blooming (especially Nemesia). For seed collection: allow flowers to fade and develop seed pods, harvest when dry and brown, store in cool, dry place.

Fun Facts

🌱 Nemesia flowers are snapdragon-like and come in nearly every color imaginable—some varieties feature stunning bi-color and tri-color patterns, with throat markings that guide pollinators.
🌱 Many Sundrops (Oenothera) species are evening bloomers, opening their flowers in late afternoon and evening hours, and are also called Evening Primrose—though they're unrelated to common primrose plants.
🌱 Nemesia is native to South Africa and thrives as a cool-season annual in most climates, making it an excellent spring or fall choice when summer annuals struggle in heat.

Gardening Terms

New to gardening? Learn about terms used in this guide:

Annual Bolt Deadhead Full Sun Partial Shade Perennial Pinch Back True Leaves

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