Trailing Lobelia, also known as Edging Lobelia
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.
Seed Treatment:
To boost germination consistency, you may soak seeds in warm water for a few hours before sowing, though this is optional.
When to Sow:
Indoors: Start seeds 8–10 weeks before the last frost.
Outdoors: Sow after all danger of frost has passed (less common due to small seed size and need for controlled conditions).
Sowing Instructions:
• Do not cover the seeds—surface sow only.
• Gently press seeds into the surface of moist seed-starting mix
• Use grow lights to maintain 12–16 hours of light per day.
• Ideal temperature: 65–75°F (18–24°C)
• 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.
• Germination in 14–35 days
Watering:
• Keep soil consistently moist, but not soggy. Water gently or mist to avoid displacing seeds
Spacing:
• Thin or transplant seedlings 4–6 inches (10–15 cm) apart
Light Requirements:
Prefers full sun to partial shade.
In hot climates, provide afternoon shade to prolong blooming.
Soil Requirements:
Needs moist, rich, well-draining soil.
Ideal pH: 6.0–7.0
Growing Tips:
• Produces masses of tiny flowers
• Perfect for hanging baskets, window boxes, containers, and borders
• May slow down in peak summer heat—cut back to refresh blooms
• Often grown as an annual, though perennial in frost-free zones
• Hardy in USDA Zones 10–11, typically grown as annual elsewhere