How to grow Onion in Australia

Grow in full sun in firm, fertile, free-draining soil, spacing sets or seedlings about 10cm apart. Keep beds weed-free, as onions hate competition, and water steadily while the tops grow.

At a glance

Difficulty: Intermediate
Sun: Full sun
Water: 3 litres a week, watered every 3 days
Spacing: 10 cm
Time to harvest: 180 days
Time to germinate: 12 days
Soil pH: 6 to 7
Frost tolerance: Half hardy

When to sow by region

Region	When to sow	Regional note
South East Queensland	March to June
Northern Rivers NSW	March to June
Sydney & Coastal NSW	March to May	Cool-season window aligned with Sydney; reliable winter harvest.
Melbourne & Victoria	March to September	Variety stagger: early types Mar to May, mid-season Jun to Jul, late keepers Jul to Sep. Long cool season perfect for bulbing.
Adelaide & SA	March to September	Variety stagger: early types Mar to May, mid season May to Jul, late keepers Jul to Sep. Grow from seed or seedlings; the long cool season bulbs them well.
Perth & WA	April to June	Mediterranean: narrow window to Apr to Jun. Onions planted as sets; avoid warm-season sowing.
Tasmania	July to September	Sow Jul to Sep. Long-day varieties suit Tasmania and bulb up in the long summer daylight. Harvest late summer.
Canberra & ACT	April and May, August and September	Stagger: sow early varieties Apr to May, mid and late varieties Aug to Sep. Harvest summer when tops fall.
North Queensland	April to June	Dry season only. Long crop cycle; sow Apr to Jun for Apr to Aug/Sep harvest.
Darwin & Top End	April to June	Dry season only. Long crop cycle; sow Apr to Jun for Apr to Aug/Sep harvest.

Varieties

Early Cream Gold
Red Tropicana
Spring Onion (Straight Leaf)

Companion planting

Good companions

Avoid planting near

Harvest and storage

Harvest tip

Lift once the tops yellow and flop over at the neck. Loosen with a fork and ease the bulbs out, then cure in a dry airy place before storing.

Storage

Dry, cool, dark place, up to 3 months. Do not refrigerate until cut.