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 room-temperature water for 24 hours before sowing.
When to Sow Indoors
Start seeds indoors 8–10 weeks (56–70 days) before your last expected frost. In warm, frost-free climates, seeds can be started indoors anytime with adequate light.
When to Sow Outdoors
Direct sowing is only recommended in warm climates (USDA Zones 9–11) after all danger of frost has passed and soil temperatures are consistently warm (above 20°C / 68°F). Sow on the soil surface and lightly press in—do not deeply cover.
Optimum Germination Temperature: Use a heat mat to maintain steady temperatures of 20–25°C (68–77°F)
Germination Time: Up to 42 days
Light Requirements for Germination
Seeds require light to germinate. Do not bury deeply—press gently into the surface and cover very lightly with fine vermiculite if needed.
Use grow lights to maintain 12–16 hours of light per day.
How to Sow Indoors
Use a sterile, well-draining seed-starting mix.
Moisten soil evenly before sowing.
Place seeds on the surface and press gently into the soil. Cover only very lightly.
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
Provide bright light and good airflow to prevent legginess.
Keep soil lightly moist but never waterlogged.
Transplant into individual pots once seedlings have 2–3 true leaves.
Harden off gradually over 7–10 days before moving outdoors.
Final Plant Spacing
Space plants 60–90 cm (24–36 inches) apart.
Plant Type
Tender perennial shrub (evergreen in warm climates, often grown as an annual in cooler regions).
Mature Height
1.5–3 m (5–10 feet), can be pruned to maintain size.
Growing Tips
Prefers full sun for best flowering (minimum 6 hours daily).
Thrives in well-draining soil; tolerates drought once established.
Blooms continuously from late spring through autumn in warm climates.
Can be grown in large containers and overwintered indoors in colder zones.
Prune regularly to encourage bushy growth and abundant flowers.
More guides at: bloomoutlet.com/seed-guides