When to Plant Amaranth in Brisbane — Subtropical Guide
Photo: Wikimedia Commons
Amaranth is a heat-loving leafy green and grain crop originating from Central America, now widely grown across tropical and subtropical Australia. Leaf amaranth varieties produce abundant, nutritious greens rich in iron, calcium and vitamins A and C. It thrives where lettuce and spinach bolt, making it the go-to summer green for warm climates.
Planting Calendar
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| S/T/D | S/T/D | S/T/D | T | — | — | — | S/T/D | S/T/D | S/T/D | S/T/D | S/T/D |
S = Seed Tray T = Transplant D = Direct Sow
Current Growing Conditions
Soil temperature: 23.6°C (optimal range: 18–35°C) ✓ Ready to plant
How to Grow Amaranth in Subtropical Australia
When to Plant
Sow September-March. Peak growing period October-February. Can extend to April with warm autumn. Too cold for germination May-August.
- Soil
- Well-drained, fertile loam enriched with compost. Tolerates a wide range of soils including sandy and clay, provided drainage is adequate.
- pH Range
- 6.0-7.5
- Sunlight
- Full sun (minimum 6-8 hours). Will tolerate light afternoon shade in extreme heat.
- Spacing
- 25cm apart, 45cm between rows
- Watering
- Water deeply 2-3 times per week once established. Drought tolerant once mature but produces best leaf quality with consistent moisture. Avoid waterlogging. Drip irrigation preferred.
Companion plants: Corn, Tomato, Eggplant, Lettuce (amaranth provides shade), Marigold
Avoid planting near: Brassicas (nutrient competition), Fennel
Subtropical Growing Tips for Amaranth
Recommended Varieties
- Edible Red
- Golden Giant (grain)
- Red Leaf
- Joseph's Coat
Key Challenges
- Flea beetles in warm weather
- Bolting to seed in late summer heat (harvest young)
- Drought stress in dry springs
Pro Tips
- Ideal summer substitute for cool-season greens in SEQ
- Sow successionally every 3 weeks for continuous baby leaf harvest
- Mulch heavily to retain soil moisture through dry springs
Harvesting Amaranth
When ready: Leaf amaranth: harvest when leaves are 10-15cm long for baby greens, or let plants reach 30-40cm for full-size leaves. Grain amaranth: harvest when seed heads droop and seeds fall easily when rubbed.
How to harvest: Cut-and-come-again: cut leaves or tops 10cm above ground level and plants will reshoot. For grain: cut entire seed heads, dry in paper bags, thresh by rubbing between hands.
Common Amaranth Pests in Subtropical Zones
Organic prevention: Companion plant with marigolds and basil. Maintain good garden hygiene. Remove amaranth family weeds. Delay planting until soil is warm; vigorous seedlings outgrow damage.
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