How to Grow Double Scarlet Nasturtium

Double Scarlet Nasturtium

Tropaeolum majus 'Double Scarlet'

flower

Double Scarlet Nasturtium is a vibrant ornamental variety featuring fully double (multi-petaled) bright red-scarlet flowers that bloom profusely throughout the growing season. This fast-growing annual produces attractive round, blue-green foliage and thrives in warm conditions, making it an excellent choice for borders, containers, and hanging baskets. The plants are non-climbing or semi-trailing, offering a more compact habit than some nasturtium varieties.

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Example Double Scarlet Nasturtium timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Double Scarlet Nasturtium

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. First Double Scarlet Nasturtium blooms

    Around Jun 1

    ≈ 45 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Double Scarlet Nasturtium dates for your own zip code.

Growing Conditions

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Sun: Full sun to partial shade; 6+ hours of direct sunlight daily for best flowering
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Water: Moderate watering; allow soil to dry slightly between waterings. Overwatering reduces flowering. Drought-tolerant once established.
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Spacing: 12-18 inches
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Days to maturity: 45-60 days to first blooms
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Planting depth: 0.5 inches

Soil

Type: Well-draining, moderately fertile loamy soil
pH: 6.0-7.0
Amendments:
Compost peat moss perlite for container growing

Growing Zones

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Thrives in zones 2-11; best in cooler zones 3-8 to prevent heat stress

2a 2b 3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a 10b 11a 11b

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Growth Stages

1

Seedling

2-3 weeks

Cotyledons emerge with distinctive round seed leaves. True leaves develop quickly with characteristic round, shield-like shape.

Thin seedlings to proper spacing early. Keep soil consistently moist but not waterlogged. Provide bright light.

2

Vegetative Growth

3-4 weeks

Plant develops bushy growth with abundant round foliage. Stems thicken and branches proliferate. No flowers present yet.

Pinch back growing tips to encourage bushier growth. Reduce nitrogen fertilizer to avoid excessive foliage at expense of blooms. Water moderately.

3

Budding

1-2 weeks

Flower buds form in leaf axils, appearing as small green knobs. Buds gradually enlarge and begin showing color.

Maintain consistent watering schedule. Shift to balanced or phosphorus-rich fertilizer to support flower development. Continue deadheading nearby spent flowers if present.

4

Flowering

6-10 weeks (continuous until frost)

Fully double scarlet flowers open with multiple layers of petals creating a pompom or rose-like appearance. Blooms are abundant and continuous.

Deadhead spent flowers regularly to encourage more blooms. Water consistently. Avoid excessive heat stress. Monitor for pests. Stake or support if needed.

5

Seed Development

3-4 weeks after flowering

If flowers are not deadheaded, distinctive round seed pods form (typically in groups of three). Seeds mature from green to brown.

Allow select flowers to remain for seed collection if desired. Collect seed pods when brown but before they split. Store seeds in cool, dry location for next season.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Brassicas (cabbage, broccoli, cauliflower) Fennel

Common Pests

  • Spray with water to dislodge; use insecticidal soap; encourage beneficial insects like ladybugs; neem oil spray as needed

  • Increase humidity; spray leaves with water; use miticides or neem oil; remove heavily infested leaves

  • Yellow sticky traps; insecticidal soap; neem oil; strong water spray; reflective mulches

  • Hand-pick larvae; Bacillus thuringiensis (Bt) spray; row covers; encourage natural predators

  • and

    Hand-pick in early morning or evening; beer traps; copper tape barriers; diatomaceous earth; encourage predators

Uses

🍳

Edible Flowers & Garnish

Culinary

Both the brilliantly colored double scarlet flowers and round leaves are edible with a peppery, slightly spicy flavor. Flowers make stunning garnishes for salads, desserts, and dishes, while leaves add peppery notes to fresh greens. [source]

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Peppery Leaf Salads

Culinary

The round shield-shaped leaves are crisp and tender with a pleasant peppery taste similar to watercress. Young leaves are best harvested before flowering and used fresh in salads. [source]

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Traditional Health Remedy

Medicinal

Nasturtium leaves and flowers contain glucosinolates and have been used traditionally in herbal medicine for their antimicrobial and immune-supporting properties, though scientific evidence is limited. [source]

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Natural Pest Control

Household

Nasturtiums act as trap crops, attracting aphids and other pests away from vegetable gardens. They're often planted as companion plants to protect more valuable crops from insect damage. [source]

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Pollinator & Hummingbird Attraction

Wildlife

The abundant double scarlet flowers attract bees, butterflies, and hummingbirds throughout the blooming season, making this plant valuable for supporting pollinator populations and creating a vibrant garden ecosystem. [source]

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

Harvest Tips

Nasturtiums are grown primarily for ornamental flowers rather than harvesting. Deadhead spent blooms regularly to extend flowering season. For seed collection, leave some flowers unpruned and harvest seed pods when they turn brown and papery but before they split open and shatter seeds.

Fun Facts

  • 🌱 Double Scarlet Nasturtium flowers contain sulfur compounds (glucosinolates) that give them a naturally peppery flavor, making them one of the few ornamental flowers that are both beautiful and edible with actual culinary value.
  • 🌱 Nasturtium seeds were historically used as a substitute for capers, pickled and preserved as 'poor man's capers' in European cuisine, offering a creative way to extend the plant's usefulness beyond just the flowers.
  • 🌱 The plant's scientific name 'Tropaeolum' comes from the Greek word 'tropaion' meaning 'trophy,' referring to how the round leaves were thought to resemble shields and the flowers resembled helmets worn by ancient warriors.

Gardening Terms

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

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