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.
When to Sow Indoors
Sow indoors 8–10 weeks (56–70 days) before the last expected frost.
When to Sow Outdoors
Not recommended. Indoor sowing provides significantly better germination and seedling survival.
Optimum Germination Temperature: Use a heat mat to maintain steady temperatures of 18–22 °C (64–72 °F)
Germination Time: Up to 21 days
Light Requirements for Germination: Light required. Do not cover seeds. Use grow lights to maintain 12–16 hours of light per day.
How to Sow Indoors
• Use a fine, well-draining seed-starting mix
• Surface-sow seeds and gently press them into the soil—do not cover
• Water from below or mist gently to avoid displacing 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 once seedlings have several true leaves
• Harden off gradually before moving outdoors
• Final plant spacing: 20–25 cm (8–10 in)
• Plant type: Tender perennial (often grown as an annual)
• Mature height: 30–45 cm (12–18 in)
• Pinch young plants to encourage bushier growth and more blooms
Growing Tips
• Prefers full sun to light shade
• Best performance in cool to mild temperatures
• Deadhead regularly to extend flowering
• Ideal for containers, hanging baskets, and borders
• Avoid waterlogged soil—consistent moisture with good drainage is key
More guides at: bloomoutlet.com/seed-guides