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 STRATIFY: 1–2 weeks at 4°C (39°F) Store in a damp paper towel or damp sand in the refrigerator. If seedlings sprout in the fridge, remove them gently and plant immediately.
• Seeds are very fine and should be surface sown.
• Optionally, soak in room-temperature water for 6–12 hours to improve moisture absorption.
• Do not cover the seeds with soil — they need light to germinate.
When to Sow:
Indoors (Recommended for earlier blooms):
-
Late winter to early spring: Start seeds 6–8 weeks before your last frost date.
Outdoors (Direct sowing):
-
Spring: After the danger of frost has passed
-
Fall (mild climates only): September–October
Fall sowing can help natural stratification and early sprouting in spring.
Sowing Instructions:
• Use a fine, well-draining seed-starting mix.
• Gently press seeds into the surface of moist soil — do not bury.
• 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.
• Maintain a temperature of 18–22°C / 65–72°F.
• Typical germination time: 10–14 days
• Maximum germination time: up to 35 days, especially if temperatures fluctuate or moisture is inconsistent.
Light Requirements:
• Prefers full sun for best flowering and compact growth.
• Seedlings also need bright light — use a sunny windowsill or grow light indoors.
Soil Requirements:
• Tolerates poor, sandy, or dry soil but prefers well-draining, average garden soil.
• pH range: 5.5–7.5
Watering:
• Keep the soil lightly moist during germination.
• Once established, drought-tolerant — water only during prolonged dry spells.
Spacing & Transplanting:
• Transplant when seedlings have at least 2–3 sets of true leaves.
• Space plants 18–24 inches (45–60 cm) apart.
Growing Tips:
• Produces large, flat clusters of bright yellow flowers and attractive fern-like foliage.
• Blooms in mid to late summer.
• Great for cut flowers, borders, and pollinator gardens.
• Deadhead spent blooms to extend flowering.
• Hardy in USDA Zones 3–9.
• May self-seed mildly if not deadheaded.