When to Plant Amaranth in Sydney — Warm Temperate 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 | T | — | — | — | — | — | S/D | S/T/D | S/T/D | S/T/D |
S = Seed Tray T = Transplant D = Direct Sow
Current Growing Conditions
Soil temperature: 19.3°C (optimal range: 18–35°C) ✓ Ready to plant
How to Grow Amaranth in Warm Temperate Australia
When to Plant
Sow October-January after soil warms to 18C+. Short growing season compared to tropics. Start in trays indoors from September.
- 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
Warm Temperate Growing Tips for Amaranth
Recommended Varieties
- Red Leaf Amaranth
- Alegria (grain)
- Golden Giant
Key Challenges
- Short season limits grain production
- Cool nights can slow growth in spring and autumn
- Less vigorous than in warmer zones
Pro Tips
- Start seeds indoors on heat mat for earlier transplanting
- Use black plastic mulch to warm soil faster in spring
- Focus on leaf varieties rather than grain types for reliable harvest
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 Warm Temperate 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.
Get the Full Interactive Guide
Open the interactive planting dashboard with real-time weather, all pest alerts, and garden tracking.
Join Garden Buddy for premium features: disease management, seed saving, preservation guides,.