When to plant Spring Onion in Cool Australia

Cool zone — applies to Hobart, Canberra, Ballarat, Orange, Armidale and similar areas. Growing elsewhere? Tropical · Temperate · Subtropical · Arid.

Spring onions have a shorter window than most alliums in the cool zone: sow direct from September to December, once spring soil has started to warm. Germination is reasonably brisk at 7–14 days and the crop turns around in 60–70 days, which makes them one of the quicker rewards in an Armidale or Orange spring garden. Sow 10 mm deep in rows 20–30 cm apart and thin to 5–10 cm. Because the window is compact, succession sowing every few weeks from September matters more here than it does in warmer zones.

Sowing calendar — cool zone

Green months are your sowing window: September to December.

Growing notes

The spring-only window is really about soil temperature. In cold districts like Armidale or Ballarat, the ground stays too cold for reliable germination until September, and the season's sowings need to be in by December so plants mature in decent conditions. The plants themselves are hardy — a December sowing that matures into March and April will stand happily through the first autumn frosts, and in fact spring onions left in the ground past the late-April frost date just get a little stronger in flavour rather than collapsing.

Within the window, early sowings (September–October) germinate more slowly at the cold end of the 7–14 day range but give you spring onions by early summer; November–December sowings race up in warm soil and carry the supply into autumn. Sowing a short row every three to four weeks is the difference between a glut and a steady kitchen supply.

They want a sunny bed with fine, well-drained soil — clods and crust stop the thin seedlings emerging, which is the most common failure. Rake the seedbed to a fine tilth, sow at a consistent 10 mm, and keep it moist until emergence. The other frequent mistake is losing slow, grass-like seedlings to weeds; a marked row and an early careful hand-weed prevent it. Harvest whole plants at pencil thickness from about 60 days.

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 do you plant spring onions in cool climate areas?

Sow direct from September to December, once spring soil has warmed. Sow a short row every three to four weeks across that window for a continuous supply from early summer into autumn.

Why didn't my spring onion seeds germinate?

Cold or crusted soil is the usual cause. Wait until September, rake the bed to a fine tilth, sow 10 mm deep, and keep the surface moist — expect emergence in 7–14 days.

How long do spring onions take from seed to harvest?

About 60–70 days. Start pulling them at pencil thickness; they can stay in the ground beyond that and will even tolerate early autumn frosts without spoiling.

Can I grow spring onions through winter in Armidale?

Sowing stops in December, but plants standing in the bed will handle frost — they are hardy. For winter sowings the soil is simply too cold for germination, so wait for September.

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