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: Soak seeds in warm water for 4 hours.
When to Sow Indoors: Start indoors 6–8 weeks (42–56 days) before the last expected frost.
When to Sow Outdoors (for natural conditions):
Sow outdoors only after the danger of frost has passed and soil has warmed to at least 18 °C (65 °F). Basil is frost-sensitive and will not germinate in cold soil.
Optimum Germination Temperature:
Use a heat mat to maintain steady temperatures of 22–28 °C (72–82 °F)
Germination Time: Up to 21 days (under optimal conditions)
Light Requirements for Germination:
Light aids germination—press seeds gently onto the surface of the soil without covering them.
Use grow lights to maintain 12–16 hours of light per 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.
How to Sow Indoors:
Use a fine, well-draining seed-starting mix. Sow seeds on the surface and mist lightly to settle them in.
Maintain steady warmth and bright light until germination. Once seedlings have 2–3 true leaves, transplant into individual pots.
Post-Germination Care:
- Transplant Outdoors: After all frost danger has passed and nighttime temps stay above 10 °C (50 °F).
- Spacing: 20–30 cm (8–12 in) apart.
- Type: Tender annual herb.
- Mature Height: 30–60 cm (12–24 in).
- Soil: Fertile, well-draining soil rich in organic matter.
- Sunlight: Full sun (minimum 6 hours daily).
- Water: Keep evenly moist but not soggy.
Growing Tips:
- Pinch off flower buds early to encourage more leafy growth.
- Harvest leaves regularly to promote bushiness.
- Avoid overhead watering to reduce risk of fungal disease.
- For continuous harvests, sow new seeds every 3–4 weeks.
More guides at: bloomoutlet.com/seed-guides