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 (Before Planting)
Sow seeds directly on the surface of moist soil. Do not cover—light aids germination.
SOAK in warm water for 4–6 hours.
Optimum Temperature
Use a heat mat to maintain temperatures at 64–72°F (18–22°C) for best germination results.
Germination Time
Usually germinates in 14–30 days.
Light Requirements
Use grow lights to maintain 12–16 hours of light per day.
How to Sow
Use trays or pots with well-draining seed starting mix. Sow on the surface and gently press seeds into the soil. Mist lightly to keep moist.
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 as needed to maintain surface moisture.
Post-Germination Care
Once seedlings appear, place in a bright, cool location. Thin or transplant when they have 2–3 true leaves. Gradually acclimate to outdoor conditions before planting out.
Transplanting Outdoors
Transplant in spring or fall when temperatures are mild. Space 12–15 in. (30–38 cm) apart. Prefers full sun to partial shade and well-drained soil.
Bloom Time
Biennial – sow in late spring to bloom the following year (early summer).
Notes
Deadhead spent blooms to extend flowering. May self-seed in the garden under favorable conditions.