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 warm water (about 30 °C / 86 °F) for 12–24 hours before sowing.
When to Sow Indoors:
Start indoors 6–8 weeks (42–56 days) before the last expected frost.
When to Sow Outdoors (for natural conditions):
Sow directly outdoors only after all danger of frost has passed and soil is warm (above 18 °C / 65 °F).
Optimum Germination Temperature: Use a heat mat to maintain steady temperatures of 22–28 °C (72–82 °F)
Germination Time: up to 21 days
Light Requirements for Germination:
Requires light to germinate — press seeds gently into the surface of the soil without covering.
Use grow lights to maintain 12–16 hours of light per day.
How to Sow Indoors:
Sow on the surface of moist, sterile seed-starting mix. Do not bury the seeds—light aids germination. Keep medium consistently moist but not waterlogged.
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:
Transplant seedlings outdoors once they are 7–10 cm (3–4 in) tall and all frost danger has passed. Space plants 30–45 cm (12–18 in) apart.
Type: Annual
Mature Height: 90–150 cm (3–5 ft)
Prefers full sun and well-draining, moderately fertile soil. Water regularly during dry periods but avoid overwatering.
Growing Tips:
Pinch young plants to encourage bushier growth.
Amaranth tolerates heat and drought once established. For edible leaves, harvest when young and tender; for ornamental or grain purposes, allow flower heads to mature fully before collecting seeds.
More guides at: bloomoutlet.com/seed-guides