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:
• Cold stratification is recommended: Place seeds in moist sand or vermiculite, seal in a plastic bag, and refrigerate at 35–40°F (1–4°C) for 2–4 weeks.
• Check weekly: If seedlings sprout in the fridge, remove them gently and plant immediately.
• Alternatively, sow outdoors in fall for natural stratification.
• Seeds are tiny and need light to germinate—do not cover deeply.
When to Sow:
• Indoors: Start seeds 6–8 weeks before the last frost after stratification.
• Outdoors: Direct sow in fall or early spring.
Sowing Instructions:
• Surface sow seeds—press them gently onto the soil surface but do not cover, as they require light to germinate.
• Use a fine, moist seed-starting mix and mist to keep moist.
• Use grow lights to maintain 12–16 hours of light per day.
• Use a heat mat to maintain steady temperatures of 20–24°C (68–75°F).
• Germination typically occurs in 28-60 days AFTER stratification.
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.
Light Requirements:
• Prefers full sun for best growth and flowering.
Soil Requirements:
• Tolerates a wide range of soils but prefers well-draining, moderately fertile soil.
• pH range: 6.0–7.5.
• Tolerates dry or sandy soil once established.
Watering:
• Keep soil consistently moist during germination and early seedling stages.
• Mature plants are drought-tolerant and only need occasional watering.
Spacing:
• Thin or transplant seedlings to 12–18 inches (30–45 cm) apart.
Growing Tips:
• Produces tall spikes in summer.
• Attracts bees and pollinators.
• Great for cottage gardens, wildflower meadows, and borders.
• Biennial or short-lived perennial in USDA Zones 4–9.