When to Plant Amaranth in Melbourne — Cool Temperate Guide

Amaranth

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: 21.9°C (optimal range: 18–35°C) ✓ Ready to plant

How to Grow Amaranth in Cool Temperate Australia

When to Plant

Short season: sow November-January only. Start indoors from October. Not a reliable crop in this zone.

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

Cool Temperate Growing Tips for Amaranth

Recommended Varieties

  • Red Leaf Amaranth
  • Joseph's Coat

Key Challenges

  • Very short growing season
  • Cool nights inhibit growth
  • Rarely produces grain reliably

Pro Tips

  • Grow in greenhouse or polytunnel for best results
  • Treat as baby leaf crop; don't expect large plants
  • Warm soil with black plastic before planting

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 Cool Temperate Zones

Aphids and Whiteflies — Risk: MODERATE (score: 45/100)

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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