For optimal germination rates, initiate seed propagation indoors under controlled conditions—unless the species exhibits a high sensitivity to root disturbance. This approach allows precise regulation of temperature, humidity, and light, improving germination consistency and seedling viability. Do not skip any recommended seed treatments, as they are essential for uniform and successful germination.
Seed Treatment:
• Soak seeds in warm water for 4–6 hours before sowing.
When to Sow:
• Outdoors: Sow directly into the garden in early spring after the last frost or in late summer to fall in mild climates.
• Indoors: Start seeds 4–6 weeks before the last frost date.
Sowing Instructions:
• Sow seeds ¼–½ inch (6–12 mm) deep in well-draining soil.
• Cover lightly and water gently.
• Use grow lights to maintain 12–16 hours of light per day.
• Humidity: Use a humidity dome or clear cover to maintain consistent moisture during germination. Open the dome BRIEFLY once per day to allow fresh air in and reduce mold risk. Remove the dome entirely once seedlings emerge.
• Ideal germination temperature: 60–70°F (15–21°C).
• Germination occurs in 21-28 days.
Light Requirements:
• Prefers full sun, but tolerates partial shade—especially in hot climates.
Soil Requirements:
• Grows well in average, well-draining soil.
• pH range: 6.0–7.0.
• Avoid overly rich soil to prevent leggy growth.
Watering:
• Water regularly to keep soil evenly moist but not soggy.
• Once established, Calendula is somewhat drought-tolerant but will flower better with consistent moisture.
Spacing:
• Thin or transplant seedlings to 12–18 inches (30–45 cm) apart.
Growing Tips:
• Produces cheerful daisy-like flowers from spring through fall.
• Deadhead spent blooms regularly to prolong flowering.
• Ideal for pollinator gardens, edible landscapes, and medicinal herb beds.
• Calendula petals are edible and often used in teas, salads, and skin salves.
• Grows as a hardy annual but may self-seed readily.