When to plant Amaranth in Tropical Australia
Tropical zone — applies to Darwin, Cairns, Townsville, Broome, Mackay and similar areas. Growing elsewhere? Temperate · Cool · Subtropical · Arid.
Sow amaranth direct from February through September, and again in November, scattering the fine seed just 5 mm deep into warm, moist soil. Germination is quick and variable at 5-20 days, and the plants race to a cut-and-come-again leaf harvest in only 50-60 days. Thin or space seedlings to about 50 cm, with rows 50-80 cm apart, because a well-fed amaranth becomes a substantial plant. Whether you grow it for tender greens or the plumed seed heads, this is a crop that revels in the heat and humidity of Cairns and Townsville when many temperate leafy vegetables have long since bolted.
Sowing calendar — tropical zone
Green months are your sowing window: February to September and November.
Growing notes
Amaranth is close to the ideal tropical leaf crop: it loves heat, tolerates humidity, and grows fast enough to dodge many pest cycles. The wet season suits it, though seed sown into pounding rain can wash away or crust over, so a February-to-September run into steadier conditions gives more even stands.
The main failure mode here is letting it get away from you. In tropical warmth amaranth bolts and sets seed quickly, and once it flowers the leaves toughen and turn bitter.
- Harvest young, cutting the top growth from around 50-60 days.
- Pinch out flower spikes early if you want a longer leaf run.
- Sow small successions every few weeks rather than one big bed.
Watch for self-seeding: a single plant left to mature around Mackay can seed the whole bed and volunteer for seasons afterward. That is useful if you want a permanent patch, less so in a tidy garden. Leaf miners and the odd caterpillar chew the foliage but rarely threaten a fast crop. Give amaranth full sun, keep water up in the dry, and it will outproduce almost anything else in the summer patch.
Amaranth at a glance
| Sowing depth | 5 mm |
|---|---|
| Plant spacing | 50 cm |
| Row spacing | 50-80 cm |
| Germination | 5-20 days |
| Days to maturity | 50-60 days |
| Frost tolerance | Frost Tender |
| Method | Sow Direct |
Common questions
- Is amaranth easy to grow in tropical Australia?
- Very much so. Amaranth is one of the most reliable warm-season leaf crops for the tropics, thriving in heat and humidity that stop temperate greens. Sow direct, keep water up, and harvest young for the best leaves.
- Can you grow amaranth in the wet season in Cairns?
- Yes, amaranth handles wet-season warmth well, though heavy rain can wash away shallow-sown seed. Sow onto raised beds and expect fast germination in 5-20 days once the soil is warm.
- Why has my amaranth gone bitter?
- It has bolted to seed, which happens fast in tropical heat. Harvest leaves young from 50-60 days and pinch out flower spikes to keep new growth tender.
- How far apart should I plant amaranth?
- Space plants about 50 cm apart with rows 50-80 cm apart. They grow large in warm conditions, and crowding encourages disease and leggy, weak stems.
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