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 (Pre-Planting Preparation)
Step 1: Scarify lightly by rubbing seeds between fine sandpaper or an emery board to thin the seed coat.
Step 2: Soak seeds in lukewarm water for 12–24 hours before sowing.
When to Sow Indoors:
Start seeds indoors 6–8 weeks (42–56 days) before the last expected frost.
Optimum Germination Temperature: Use a heat mat to maintain steady temperatures of 70–75°F (21–24°C)
Germination Time: Up to 30 days
Light for Germination: Requires light — surface sow and do not bury. Use grow lights to maintain 12–16 hours of light per day.
How to Sow Indoors:
- Fill trays or pots with a well-draining seed-starting mix.
- Surface sow seeds, pressing them gently into the soil without covering.
- Mist lightly to settle seeds.
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 seedlings outdoors after all danger of frost has passed and soil is warm.
- Final Spacing: 8–12 in (20–30 cm) apart.
- Type: Tender annual.
- Mature Height: 18–24 in (45–60 cm).
- Prefers full sun and well-draining soil.
- Water moderately; drought tolerant once established.
- Deadhead spent blooms to prolong flowering. Excellent for fresh and dried arrangements.
Growing Tips:
- Harden off seedlings for 5–7 days before transplanting.
- Avoid overwatering; excess moisture can cause root rot.
- Cut flowers at peak color for longest vase life.