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 Prep:
- Soak seeds in warm water for 4–6 hours.
• Cold stratification: After soaking, place seeds in a moist paper towel and refrigerate for 7–10 days.
• Check every other day: If seedlings sprout in the fridge, remove them gently and plant immediately.
When to Sow:
• Indoors: Start 8–10 weeks before the last frost.
• Outdoors: After the last frost, or sow in late fall for spring blooms.
Light:
• Requires full sun (6+ hours/day)
• Tolerates light afternoon shade in hot zones
Soil:
• Well-drained, fertile soil
• Ideal pH: 6.2–7.0
Sowing Instructions:
• Surface sow – do not cover; press gently into soil
• Needs light to germinate
• Use grow lights to maintain 12–16 hours of light per day.
• Use a heat mat to maintain a steady temperature of 65–70°F (18–21°C)
• 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.
• Germinates in 7–28 days
Watering:
• Keep soil evenly moist during germination
• Reduce frequency once established
Spacing:
• Thin or transplant 6–12 inches apart
Tips:
• Pinch back young plants to encourage fullness
• Deadhead to prolong bloom time
• Prefers cooler weather – ideal for spring & fall gardens
• Attracts pollinators & hummingbirds