Cleome hassleriana (Spider Flower)

Seed Treatment

  • Cold Stratification:

    • Mix seeds with moist sand or peat moss in a sealed bag.

    • Store in the refrigerator (34–40°F / 1–4°C) for 1–2 weeks before planting.

  • Scarification:

    • Lightly rub seeds with sandpaper or soak them in warm water for 12 hours to speed up germination.

Sowing Instructions

Indoor Sowing (Recommended)

  1. Timing: Start seeds 4–6 weeks before the last frost.

  2. Containers & Soil: Use a well-draining seed-starting mix in seed trays or pots.

  3. Sowing Depth: Sow ¼ inch (6 mm) deep and lightly cover with soil.

  4. Watering: Keep soil moist but not waterlogged.

  5. Light & Temperature:

    • Maintain a temperature of 70–75°F (21–24°C).

    • Provide bright light for healthy seedlings.

  6. Germination Time: 7–14 days.

Direct Outdoor Sowing (Alternative)

  1. Timing: Sow after the last frost when soil temperatures are above 60°F (15°C).

  2. Location: Choose a full-sun location with well-draining soil.

  3. Sowing Depth: Sow seeds ¼ inch (6 mm) deep and lightly cover with soil.

  4. Moisture: Keep soil evenly moist until germination.

Growth & Care

  • Watering: Water regularly but allow soil to dry between watering.

  • Soil Preference: Prefers well-drained, fertile soil with a pH of 6.0–7.5.

  • Spacing: Thin seedlings to 12–18 inches apart for proper air circulation.

  • Light Requirements: Needs full sun (6+ hours daily).

  • Support: Tall plants may need staking in windy areas.

  • Bloom Time: Summer to early fall.

Cleome hassleriana is an easy-to-grow annual that attracts pollinators like butterflies and hummingbirds. It adds height, texture, and color to gardens with its unique spiky flowers! ??✨

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