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
Soak seeds in warm water for 12–24 hours before sowing.
When to Sow Indoors
Start seeds indoors 6–8 weeks (42–56 days) before the last expected frost.
Optimum Temperature for Germination: Use a heat mat to maintain a steady temperature of 72-77 °F (22-25°C)
Germination Time: 14 to 21 days
Light Requirements for Germination
Seeds need light to germinate. Use grow lights to maintain 12–16 hours of light per day.
How to Sow Indoors
Use a well-draining seed-starting mix in trays or small pots.
Surface sow the seeds and lightly press them into the soil—do not cover, as they need light.
Water gently to keep the soil evenly moist but not soggy.
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
Once seedlings develop 2–3 true leaves, gradually harden them off by exposing them to outdoor conditions over 7–10 days.
Final spacing: Plant 10–12 in. (25–30 cm) apart in full sun.
Plant type: Annual
Mature height: 12–24 in. (30–60 cm)
Growing Tips
Globe Amaranth thrives in hot, sunny locations with well-draining soil. Drought tolerant once established.
Deadheading is optional but can encourage continued blooming. Excellent for fresh or dried floral arrangements.
Avoid overwatering, especially in humid climates.