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How to Grow Red Zinnia Scarlet Splendor

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Red Zinnia Scarlet Splendor

Zinnia elegans

flower

Scarlet Splendor is a vibrant red variety of zinnia featuring double, pompom-like flowers that bloom prolifically throughout summer and fall. This annual flower is prized for its intense scarlet coloring, long stems ideal for cutting, and ability to attract butterflies and hummingbirds. It's an excellent choice for borders, containers, and fresh flower arrangements.

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Example Red Zinnia Scarlet Splendor timeline · Pittsburgh, PA (Zone 6b)

  1. Plant Red Zinnia Scarlet Splendor

    Around Apr 17

    Near Pittsburgh's average last spring frost.

  2. Tend & protect

    Late spring–summer

    Watering, feeding, and pest-watch reminders.

  3. First Red Zinnia Scarlet Splendor blooms

    Around Jun 16

    ≈ 60 days after planting

Sample dates for Pittsburgh, PA. Sign up to get exact Red Zinnia Scarlet Splendor dates for your own zip code.

Growing Conditions

☀️
Sun: Full sun, 6-8 hours daily (tolerates partial shade but performs best in full sun)
💧
Water: Moderate watering; keep soil consistently moist but not waterlogged. Water at soil level to avoid wetting foliage. Drought-tolerant once established; water less frequently in cool weather to prevent powdery mildew.
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Spacing: 9-12 inches apart inches
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Days to maturity: 60-70 days from seed to first flowers
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Planting depth: ¼ inch deep (seeds can be surface-sown); transplants at same depth as container

Soil

Type: Well-draining loamy soil with moderate fertility
pH: 6.0-7.0
Amendments:
Compost or aged manure for organic matter Perlite or sand if soil is heavy clay Balanced fertilizer (10-10-10) mixed into planting bed

Growing Zones

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Thrives in zones 3-11; grown as warm-season annual nationwide

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

7-14 days

Tiny seedlings with two oval cotyledons emerge; true leaves develop shortly after.

Keep soil warm (70-75°F) and moist. Provide bright light to prevent leggy growth. Thin seedlings to proper spacing or transplant to individual pots.

2

Vegetative Growth

3-4 weeks

Plant develops sturdy stems and compound leaves; bushy form emerges. No flowers present yet.

Pinch off the top ¼ inch when plants are 6 inches tall to encourage branching and bushier shape. Maintain consistent moisture and full sun. Fertilize lightly every 2-3 weeks.

3

Flowering Initiation

2-3 weeks

Flower buds form at branch tips; first blooms appear as tight green buds swelling noticeably.

Continue regular watering and fertilizing. Deadhead spent flowers to encourage continued blooming. Support tall stems with stakes if needed.

4

Peak Blooming

8-12 weeks (extends with deadheading)

Vibrant scarlet double flowers in full pompom form cover the plant. Continuous flowering throughout season.

Deadhead regularly (every 2-3 days) to maximize bloom production. Water at soil level to keep foliage dry and prevent fungal issues. Continue fertilizing every 2-3 weeks.

5

Late Season/Decline

Until frost

Flowering slows as temperatures cool in fall. Plants may show reduced vigor and flower size.

Continue deadheading to extend season. Reduce fertilizer. Collect seeds from mature flower heads if desired before frost. Plant dies at first hard frost.

Companion Planting

Plan your garden →

Plant with:

Salvia Dusty Miller Marigold Cosmos Cleome Sweet Alyssum Larkspur Bachelor's Button

Avoid planting near:

Fennel (allelopathic, inhibits many plants) Dill (can cross-pollinate zinnias) Other Zinnia varieties (if saving pure seed)

Common Pests

  • Spray foliage with water to increase humidity; use neem oil or insecticidal soap if severe. Avoid overhead watering which creates conditions favoring mites.

  • Ensure good air circulation; avoid wetting foliage when watering. Apply sulfur dust or baking soda spray (1 tbsp per gallon water) at first sign. Remove affected leaves.

  • Spray with strong water stream; use insecticidal soap or neem oil. Encourage beneficial insects like ladybugs.

  • Hand-pick in early morning; use neem oil or kaolin clay spray. Avoid Japanese beetle traps near zinnias.

  • Spray underside of leaves with neem oil or insecticidal soap. Yellow sticky traps can help monitor and trap adults.

Uses

🍳

Edible Flowers & Garnish

Culinary

Zinnia petals are edible with a slightly peppery flavor and can be used to garnish salads, desserts, and cocktails. The vibrant scarlet color makes them particularly striking as a fresh garnish. [source]

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Cut Flowers & Arrangements

Craft

Scarlet Splendor's long stems and full double blooms make it an excellent choice for fresh flower arrangements, bouquets, and floral design. Flowers last exceptionally long in water when harvested properly. [source]

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Pollinator Attractor

Wildlife

Despite the double flower form, zinnias attract butterflies, hummingbirds, and bees seeking pollen and nectar. Scarlet flowers are particularly attractive to hummingbirds due to their color. [source]

🏠

Dried Flowers & Crafts

Household

Zinnia flowers dry well and can be used in dried arrangements, wreaths, and craft projects. They retain color and form when dried, making them ideal for long-lasting floral displays. [source]

💊

Traditional Herbal Remedy

Medicinal

In traditional Chinese and Ayurvedic medicine, zinnias have been used as herbal remedies for inflammation and immune support, though scientific evidence is limited. Consult healthcare providers before medicinal use. [source]

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

Harvest Tips

Cut flowers in early morning when fully open for longest vase life (7-10 days). Cut stems at a 45-degree angle and remove lower leaves below the waterline. Cutting regularly encourages more blooms. For seed saving, allow some flowers to dry on the plant; seeds mature about 4 weeks after flowering. Collect dried seed heads and extract seeds when fully brown and papery.

Fun Facts

  • 🌱 Zinnias are named after Johann Gottfried Zinn, an 18th-century German botanist and physician, and were originally native to Mexico and Central America.
  • 🌱 The 'Scarlet Splendor' variety was developed through selective breeding to produce the most vibrant, saturated red color and full double-flower form.
  • 🌱 Zinnias are one of the few flowers that actually improve in appearance after being cut; the remaining plant becomes bushier and produces even more flowers within days of cutting.

Gardening Terms

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

Annual Deadhead Full Sun Partial Shade Transplant True Leaves
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