When to plant Spring Onion in Arid Australia

Arid zone — applies to Alice Springs, Mildura, Broken Hill, Kalgoorlie, Port Augusta and similar areas. Growing elsewhere? Tropical · Temperate · Cool · Subtropical.

Spring onions sow direct from July to December in the arid zone — winter through early summer — at 10 mm deep. They're one of the quicker alliums, germinating in 7–14 days and ready to pull in 60–70 days, so a July sowing in Port Augusta is on the table by September, and successive sowings every three or four weeks keep the supply running into summer. Fully hardy, they ignore frosty inland nights entirely. Their shallow roots are the arid-zone catch: the top few centimetres of soil where they live is exactly the layer that dries out fastest.

Sowing calendar — arid zone

Green months are your sowing window: July to December.

Growing notes

Everything about spring onions happens in the top 10 cm of soil, which in Broken Hill in November can go from damp to dust in a day. That shapes the whole approach: sow into soil enriched with compost so it holds moisture, mulch lightly between rows — fine straw at 30–40 mm, since heavy mulch smothers the thin seedlings — and water little and often rather than the deep-soak rhythm that suits deeper-rooted crops. This is the one vegetable where a light daily watering in warm weather is the right call, not a bad habit.

The July-to-December window splits into two seasons. July-to-September sowings are nearly foolproof: cool soil, frost no threat to this fully hardy crop, and steady growth to harvest in 60–70 days. November and December sowings are the gamble — germination is fast at 7–14 days, but emergence into 40°C wind kills seedlings quickly, so give late sowings afternoon shade from day one.

The standard failure is a patchy, wispy row from seed sown too deep or too thick. Keep to 10 mm — deeper sowings in crusting arid soils often never surface — and thin to 5–10 cm so each plant can thicken. Pull the biggest first and let the rest grow on; one sowing can stretch across a month of harvests.

Spring Onion at a glance

Companion planting

Grows well with

Carrot: Scent deters carrot fly

Keep away from

Bean (Bush): Alliums inhibit legume growth

Common questions

When should I plant spring onions in Port Augusta?

Sow direct from July to December. The July-to-September sowings are the easiest; later sowings need afternoon shade to get seedlings through the heat.

How often should I water spring onions in hot weather?

Lightly and often — even daily in warm months. Their roots sit in the top few centimetres of soil, which dries out faster than deep watering can fix.

Why didn't my spring onion seed come up?

The usual causes are sowing deeper than 10 mm or a soil crust forming over the seed. Keep the surface moist for the full 7–14 day germination and sow shallow.

How long do spring onions take to grow?

About 60 to 70 days from sowing to pulling. Sow a short row every three or four weeks for a continuous supply.

Keep exploring