How to Grow Red Begonia Scarlet Emperor

Red Begonia Scarlet Emperor

Begonia × semperflorens-cultorum 'Scarlet Emperor'

flower

Scarlet Emperor is a vibrant wax begonia cultivar prized for its brilliant red flowers and glossy, dark green foliage. This tender perennial is grown as an annual in most climates and produces continuous blooms from spring through frost. It's an excellent choice for bedding, containers, and shaded gardens.

Growing Conditions

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Sun: Partial shade to dappled sunlight; 2-4 hours of morning sun ideal. Too much direct sun can scorch leaves in hot climates.
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Water: Keep soil consistently moist but not waterlogged. Water when top inch of soil is dry. Reduce watering in winter if overwintering indoors. Prefer humidity; mist foliage occasionally.
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Spacing: 8 inches
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Days to maturity: 35-50 days from transplant to first blooms
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Planting depth: Plant transplants at soil level; seeds sown on surface under lights (do not cover—requires light to germinate)

Soil

Type: Well-draining loamy soil rich in organic matter
pH: 6.0-6.5
Amendments:
Compost or aged bark mulch Perlite for drainage Balanced slow-release fertilizer

Growing Zones

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Thrives in zones 10-11; grown as annual elsewhere or overwintered indoors

10a 10b 11a 11b

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Growth Stages

1

Seedling

3-4 weeks

Tiny plants with 2-4 true leaves, very delicate and slow-growing initially.

Keep under bright grow lights for 14-16 hours daily. Maintain high humidity with a dome or plastic cover. Do not allow soil to dry out. Begin gentle air circulation after germination to prevent damping-off.

2

Vegetative Growth

3-4 weeks

Plant develops multiple sets of true leaves and begins branching. Compact, bushy growth with dark green foliage.

Pinch seedlings when 2-3 inches tall to encourage branching. Maintain consistent moisture and humidity. Begin fertilizing with diluted liquid fertilizer every 2 weeks once true leaves appear.

3

Bud Formation & First Blooms

2-3 weeks

Flower buds appear at branch tips; first bright scarlet blooms emerge.

Maintain regular watering and humidity. Begin full-strength fertilizing on a weekly or bi-weekly schedule. Ensure adequate light (bright, indirect). Remove any damaged or yellowing lower leaves.

4

Flowering & Blooming

Summer through fall frost (12-16+ weeks)

Continuous production of scarlet flowers with glossy dark green foliage. Plant reaches mature size.

Deadhead spent flowers only if desired for aesthetics (not necessary for re-blooming). Water consistently. Fertilize every 7-14 days with balanced or slightly higher-phosphorus formula to encourage blooming. Watch for spider mites and powdery mildew in dry conditions.

5

Decline & Overwintering (Optional)

Fall/winter dormancy (varies)

Plants slow growth as temperatures cool and days shorten. Foliage may yellow; flowering declines.

In zones below 10, dig plants before frost and pot them indoors. Reduce watering and fertilizing. Provide bright indirect light and cool temperatures (60-65°F). Prune back in late winter to rejuvenate for spring.

Companion Planting

Plan your garden →

Plant with:

Avoid planting near:

Direct competition from aggressive shade plants like maple roots Plants requiring full sun (they will compete for light)

Common Pests

  • Increase humidity and air circulation; spray with water to dislodge. Use neem oil or miticide if severe. Isolate infested plants.

  • Improve air circulation and reduce humidity slightly. Spray with sulfur dust or potassium bicarbonate. Remove affected leaves. Avoid wetting foliage.

  • Use yellow sticky traps. Spray with insecticidal soap or neem oil. Isolate affected plants.

  • Improve air circulation and reduce excess humidity. Remove affected leaves promptly. Avoid overhead watering. Apply fungicide if severe.

  • Dab with alcohol-soaked cotton swab for small infestations. Spray with neem oil or insecticidal soap for larger infestations.

Uses

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Edible Flowers

Culinary

Begonia flowers are edible with a slightly tart, citrusy flavor and are used as colorful garnishes in salads and desserts. They add visual appeal and a delicate tang to fresh dishes. [source]

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Ornamental Bedding & Container Gardens

Household

Scarlet Emperor is widely used in shade gardens, borders, containers, and hanging baskets for continuous season-long color. Its compact habit and bright red blooms make it a popular choice for mixed plantings. [source]

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Traditional Herbal Use

Medicinal

Some cultures use begonia leaves and flowers in traditional medicine for their mild astringent and diuretic properties, though scientific evidence is limited. Often prepared as a gentle tea. [source]

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Cut Flowers & Arrangements

Craft

The scarlet blooms are attractive in fresh flower arrangements and last several days in water. Dark foliage makes an excellent background for mixed bouquets. [source]

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Pollinator Support

Wildlife

Begonia flowers attract bees and other pollinators, providing nectar and pollen especially valuable in shaded gardens where flowers are scarce. [source]

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

Harvest Tips

Begonias are ornamental flowers; deadhead (pinch off) spent blooms to encourage continued flowering, though this plant reblooms readily without it. Cut stems for fresh arrangements when desired. For overwintering, dig plants carefully before hard frost with roots intact.

Fun Facts

  • 🌱 Wax begonias like Scarlet Emperor are called 'wax' begonias because their leaves have a glossy, waxy coating that helps them retain moisture and gives them a jewel-like appearance.
  • 🌱 Begonias are native to tropical and subtropical regions and have been cultivated for centuries; they were first hybridized in Europe in the 19th century, leading to the development of many colorful bedding varieties.
  • 🌱 Scarlet Emperor and similar semperflorens begonias can technically live for several years in frost-free climates or indoors, making them long-lived perennials despite being grown as annuals in temperate zones.

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