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
Fatsia japonica seeds germinate slowly and unevenly without pre-treatment. For best results:
Cold Stratification:
• Mix seeds with moist sand, vermiculite, or paper towel
• Seal in a plastic bag and refrigerate at 35–40°F (1–4°C) for 28–42 days (4–6 weeks)
• Check weekly to ensure the medium remains moist (not soggy)
• Check regularly: If seedlings sprout in the fridge, remove them gently and plant immediately.
How to Sow Indoors
When to Sow: Start indoors immediately after stratification, ideally from late winter to early spring.
Soil: Use a well-draining mix of loam, compost, and perlite. pH 5.5–6.5 (slightly acidic).
Sowing Depth: Sow seeds ¼ inch (6 mm) deep. Cover lightly and firm the surface gently.
Temperature: Use a heat mat to maintain steady temperatures of 65–75°F (18–24°C)
Light: Light is not needed for germination, but once seedlings emerge, 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.
Watering: Keep soil evenly moist but not soggy. Mist the surface or bottom-water to avoid disturbing seeds.
Germination Time: up to 60 days after stratification. Be patient and maintain stable conditions.
Post-Germination Care
• Transplant when seedlings have 2–3 true leaves
• Final spacing: 12–24 inches (30–60 cm) apart
• Type: Evergreen shrub
• Mature height: 4–8 feet (1.2–2.4 meters)
• Ideal for shade gardens, indoor containers, or tropical landscapes
• Hardy to USDA Zones 8–11
Growing Tips
• Prefers partial to full shade
• Avoid direct sun, especially for young plants
• Water regularly but allow topsoil to dry slightly between waterings
• Protect from frost and cold drafts
• Prune lightly to shape and encourage full, bushy growth
• Avoid waterlogged soil to prevent root rot