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 2–4 weeks (14–28 days) before your last expected frost.
Optimum Germination Temperature: Use a heat mat to maintain steady temperatures of 22–26 °C (72–79 °F)
Germination Time: Up to 14 days
Light Requirements for Germination: Light required. Do not cover seeds with soil. Use grow lights to maintain 12–16 hours of light per day.
How to Sow Indoors
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Use clean seed trays or small pots with fine, well-draining seed-starting mix
• Surface-sow seeds and press gently into the soil—do not cover
• Water gently from below or mist to avoid burying 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
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Once seedlings have 2–3 true leaves, thin or transplant carefully
• Harden off gradually before moving outdoors
• Final spacing: 30–45 cm (12–18 in) apart
• Plant type: Annual
• Mature height: 1 to 6 ft (30-180 cm), depending on variety and conditions
• Full sun produces the strongest color and growth
Growing Tips
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Prefers fertile, well-drained soil
• Water regularly, especially during early growth
• Heat-loving plant—growth accelerates as temperatures rise
• Excellent for ornamental beds, cut flowers, and dramatic vertical accents
More guides at: bloomoutlet.com/seed-guides