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.
⚠️ Keep soil evenly moist during germination. DO NOT LET IT DRY OUT—once seeds begin absorbing water (imbibition), drying can kill the seed embryo, and even brief dryness after sprouting can kill seedlings.
Seed Treatment:
• Cold stratification: Place seeds in moist sand or paper towel inside a sealed plastic bag. Refrigerate at 35–40°F (1–4°C) for 2 to 4 weeks.
• Optional: Soak seeds in lukewarm water for 12 hours before cold stratification.
Check regularly: If seedlings sprout in the fridge, remove them gently and plant immediately.
When to Sow:
• Indoors: Start seeds 6–8 weeks before the last expected frost after stratification.
• Outdoors: Sow in fall for natural stratification or early spring after the risk of hard frost.
Sowing Instructions:
• Surface sow — do not cover seeds, as they need light to germinate.
• Press seeds gently into moist, well-draining seed-starting mix.
• Use grow lights to maintain 12–16 hours of light per day.
• Keep the soil consistently moist but not soggy.
• Ideal temperature for germination: 18–22°C (65–72°F).
• Germination can take 30-40 days AFTER stratification
• 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.
Watering:
• Keep soil evenly moist during germination and seedling growth.
• Once established, water moderately and avoid letting soil completely dry out.
Spacing:
• Thin or transplant seedlings to 10–15 inches (25–38 cm) apart.
Growing Tips:
• Prefers full sun to partial shade.
• More shade is tolerated in hotter climates.
• Grows best in well-draining, moderately fertile soil.
• pH range: 6.0–7.5.
• Produces elegant, nodding bell-shaped flowers on slender stems in early to mid-summer.
• Attractive in rock gardens, cottage gardens, and borders.
• Hardy perennial in USDA Zones 5–8.
• Deadhead to prolong flowering and prevent self-seeding if desired.
More guides at: bloomoutlet.com/seed-guides