When to Plant Onion in Brisbane, Subtropical Guide

Sow February, April to June and August. Right now in September it is out of season. The next sowing month is February.

Also called spring onion, scallion, shallot (the Australian name for spring onion).

Published · Last reviewed · By Garden Buddy
Growing advice is reviewed by hand. Planting dates, current conditions and prices on this page update daily.

This Onion guide is written for the Subtropical zone, which takes in Brisbane, the Gold Coast and the Sunshine Coast. Somewhere else? Your postcode picks the right one.

Not your zone? Cairns Sydney Melbourne Canberra Alice Springs Perth

Also handy: will it frost this week? and what grows in shade.

Onion

Photo: Wikimedia Commons

Onions are a staple in Australian kitchens and one of the most widely grown alliums in home gardens. Bulb formation is triggered by day length, making variety selection critical based on latitude. Short-day types suit northern Australia, while long-day types perform best in southern regions.

Planting Calendar for Subtropical

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
- S - T T/D S - T - - - -

S = Seed Tray   T = Transplant   D = Direct Sow

Want a nudge when it is Onion sowing time in Brisbane?

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Current Growing Conditions

Soil temperature: 20.4°C (optimal range: 8–30°C) ✓ Ready to plant

That figure is read off my own weather station here at Dayboro in South East Queensland at 18:55 yesterday, not a model. The radar, the rain gauge and the forecasts behind it sit on Dayboro.au.

How to Grow Onion in Subtropical Australia

When to Plant

Sow seed March-May or transplant seedlings April-June. Short-day varieties best. Some intermediate-day types will bulb in SEQ. Harvest November-January.

Soil
Well-drained, fertile loam enriched with compost. Avoid heavy clay or freshly manured soil which causes forking and soft bulbs.
pH Range
6.0-7.0
Sunlight
Full sun (minimum 6 hours direct)
Spacing
12cm apart, 30cm between rows
Watering
Consistent moisture during bulb development. Water deeply once or twice weekly. Reduce watering as tops begin to fall over (curing signal). Overhead irrigation can reduce thrips but increases fungal r

Companion plants: Carrot, Beetroot, Lettuce, Chamomile, Strawberry

Avoid planting near: Beans, Peas, Asparagus, Sage

Subtropical Growing Tips for Onion

Recommended Varieties

  • Early Lockyer White (short-day)
  • Gladalan Brown (short-day)
  • Red Tropicana (short-day)
  • Creamgold (intermediate)
  • Hunter River Brown

Key Challenges

  • Summer humidity causing storage rot
  • Thrips during dry spring weather
  • Bolting if planted too early and exposed to cold

Pro Tips

  • Short-day varieties are the safest choice for reliable bulbing
  • Plant after the hottest weather has broken (March onwards)
  • Ensure excellent drainage. Onions hate wet feet

Harvesting Onion

When ready: Tops fall over naturally and begin to yellow. Bulb skin is papery and dry. Neck tissue is thin and soft. Do not push tops over prematurely as this reduces storage life.

How to harvest: Loosen soil with a fork and lift gently. Do not pull by the tops. Lay on their side in the garden for 1-2 days if weather is dry, then move to a well-ventilated, shaded area for 2-4 weeks to cure fully. Roots and tops are trimmed after curing.

Worth growing?

A 2.4 m × 1.2 m bed fits 72 plants, about $29 worth at today’s Aldi, Coles and Woolworths prices, checked today.

That is roughly 11 kg at $2.66 a kilo.

Draw your onion bed → No account needed.

Where to next

What onion costs in the shops right now, retailer by retailer, updated daily.

Also worth sowing in the subtropical zone this September: Lemongrass, Ginger, Beetroot and Chilli Peppers.

The pest most likely to find your onion: Botrytis / Grey Mould.

Supermarket Price

Current average retail: $2.66/kg (12-month range: $1.99–$5.20)

Grow your own and save on grocery bills.

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Common Questions About Onion

When do you plant onion in Australia?

It depends on your climate zone, not the calendar month alone. Planting months by zone:

Does onion grow all year round in Brisbane?

No. In the Subtropical zone the planting months are Feb, Apr to Jun, Aug. Outside that window it either bolts, sulks or gets cut down by the weather.

What else is onion called?

Onion is the usual Australian name. Overseas seed packets and recipes call it spring onion, scallion, shallot (the Australian name for spring onion). Same plant, same growing advice.

Which zone am I in?

Type your postcode into the box under the heading and the page tells you, and links this crop in your own zone if it differs. Or look it up on the grow zone map. This page is the Subtropical zone, Brisbane is its reference city.