When to plant Leeks in Temperate Australia

Temperate zone — applies to Sydney, Melbourne, Adelaide, Perth, Newcastle and similar areas. Growing elsewhere? Tropical · Cool · Subtropical · Arid.

Leeks go in direct from August through to May in temperate Australia — only the depths of winter are off the sowing calendar. Sow the seed 10 mm deep and give it 10–15 days to germinate. This is a slow, patient crop: expect 105–120 days from sowing to harvest, so an early-spring sowing delivers autumn leeks and a late-summer sowing gives you winter ones. The reward for the wait is a vegetable that holds happily in the ground for weeks once mature, letting you pull stems as the kitchen needs them rather than facing a glut.

Sowing calendar — temperate zone

Green months are your sowing window: August to May.

Growing notes

Fully hardy, leeks treat temperate winters with indifference — frosts from May through to mid-October don't check mature plants, and many gardeners reckon a leek that has stood through cold weather eats sweeter. There's no need to lift the crop all at once; it holds in the soil until you want it.

Timing within the long window is really about when you want to harvest. Sowings from August to October mature into autumn, while late-summer and autumn sowings (January to May) grow steadily through the cool months for winter and spring pulling. With 105–120 days to maturity, count forward from your sowing date and plan the bed around it.

For the long white shank that makes a leek worth growing, blanch the stems: either sow into a shallow trench and backfill gradually as the plants thicken, or hill soil up around the stems every few weeks. Try to keep soil out of the leaf junctions, or you'll be washing grit out of dinner.

The classic failure is a bed of pencil-thin leeks, and it's nearly always crowding or hunger. Thin seedlings firmly to 10–20 cm with rows 20–30 cm apart, sow into soil enriched with compost, and keep the water steady — leeks stall in dry ground. Weed early too, because grass-like leek seedlings lose badly to actual grass.

Leeks at a glance

Companion planting

Grows well with

Carrot: Classic pairing — carrot fly repelled by leek, leek fly repelled by carrot

Carrot: Leek deters carrot fly; carrot deters leek fly — mutually protective

Celery: Both benefit from similar growing conditions; efficient space use

Common questions

When should I sow leeks in Australia?

In temperate zones, sow direct from August through to May. Allow 105–120 days to maturity, so spring sowings give autumn leeks and autumn sowings give winter ones.

How long do leeks take to grow?

Seed germinates in 10–15 days, then plants need 105–120 days to reach harvest size. They hold in the ground well once mature, so there's no rush to pull them.

Why are my leeks so thin?

Pencil-thin leeks usually come from crowding, poor soil or dry conditions. Thin to 10–20 cm apart, enrich the bed with compost and water consistently.

How do I get more white stem on my leeks?

Blanch the stems by excluding light — sow into a shallow trench and backfill as plants grow, or hill soil up around the stems every few weeks.

Can leeks stay in the ground over winter?

Yes. Leeks are fully hardy and stand through temperate frosts without protection, so you can harvest them as needed across the cold months.

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