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 a damp paper towel inside a sealed plastic bag. Store in the refrigerator (not freezer) for 2–4 weeks before planting. Check weekly: If seedlings sprout in the fridge, remove them gently and plant immediately. After stratification, allow seeds to reach room temperature before sowing.
Optional: Soaking in GA3 (Gibberellic Acid) can improve germination but may damage seeds if used incorrectly—only for experienced growers.
When to Sow Indoors: 6–10 weeks before last frost Outdoors: After last frost when soil is warm (spring)
Germination Temperature: Use a heating mat to maintain a steady temperature of 21–27°C (70–80°F)
Germination Time: up to 90 days after stratification Erratic germinator—be patient
Light Requirements for Germination Use grow lights to provide 12–16 hrs/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.
Post-Germination Care Transplant when seedlings have 2–3 sets of true leaves Space 30–45 cm apart (12–18 in) Use well-draining soil Full sun Water moderately—drought tolerant when established
Growing Tips • Deadhead to extend blooming • Excellent pollinator plant • May self-seed in warm zones • Perennial in USDA Zones 7–11 (annual elsewhere)
