When to Plant Leek in Sydney, Warm Temperate Guide

Sow January to November. Right now in October you can sow.

Planting window
Raise seed in trays and plant out when the seedlings are pencil thick, setting them deep or hilling them up to blanch the stems. Sow in...
Days to harvest
about 13 weeks
Sunlight
Full sun (6+ hours). Tolerates partial shade better than most alliums, but stems will be thinner in shade.
Water needs
Consistent moisture throughout growth. Water deeply once or twice per week. Leeks are...
Spacing
15cm apart, 40cm between rows
Soil pH
6.5-7.5

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

This Leek guide is written for the Warm Temperate zone, which takes in Sydney, Newcastle and Wollongong. Somewhere else? Your postcode picks the right one.

Not your zone? Cairns Brisbane Melbourne Canberra Alice Springs Perth

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

Leek

Photo: Wikimedia Commons

Leeks are the gentle giant of the allium family. Milder than onions, easier than garlic, and more cold-hardy than both. They occupy the garden for a long time (5-6 months from seed) but require minimal attention once established. Excellent for cool-season gardens and highly adaptable across Australian zones. A staple of winter soups, gratins, and quiches.

See what grows now in your own postcode

Planting Calendar for Warm Temperate

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

S = Seed Tray   T = Transplant   D = Direct Sow

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Current Growing Conditions

Soil temperature: 18.5°C (optimal range: 13–24°C) ✓ Ready to plant

Modelled from Open-Meteo forecast (Sydney), not a live sensor.

What this month normally looks like

In October the Warm Temperate zone normally runs 24°C by day and 13°C overnight, with about 66 mm of rain over 7 or 8 wet days. The coldest October night on record across the zone was -1.5°C, so a late frost is not out of the question. Averages 1991 to 2026, 153 postcodes, SILO.

How to Grow Leek in Warm Temperate Australia

When to Plant

Raise seed in trays and plant out when the seedlings are pencil thick, setting them deep or hilling them up to blanch the stems. Sow in late summer for winter leeks, or in winter for spring and early summer leeks.

Soil
Rich, well-drained soil with plenty of organic matter. Leeks are heavy feeders that benefit from deeply dug beds with generous compost and aged manure. Prefer neutral to slightly alkaline soil. Add lime to acidic soils.
pH Range
6.5-7.5
Sunlight
Full sun (6+ hours). Tolerates partial shade better than most alliums, but stems will be thinner in shade.
Spacing
15cm apart, 40cm between rows
Watering
Consistent moisture throughout growth. Water deeply once or twice per week. Leeks are more drought-tolerant than onions but produce thicker stems with consistent water. Reduce watering slightly in...

Companion plants: Carrot, Celery, Onion, Strawberry, Beetroot

Avoid planting near: Beans, Peas

Grow before, grow after

Leek belongs with the alliums, the roots and alliums turn of a four turn bed rotation.

Grow before it
Fruiting crops (Tomato, Capsicum, Zucchini)
Grow after it
Legumes (Beans - Dwarf, Peas, Broad Beans)

Give the bed 3 turns before alliums go back in. Onion, garlic and leek like a lean bed and clean up after the heavy feeders.

Warm Temperate Growing Tips for Leek

Recommended Varieties

  • Musselburgh
  • King Richard
  • London Flag
  • Autumn Giant

Key Challenges

  • Long growing season ties up garden space
  • Rust in humid autumn

Pro Tips

  • Sydney's climate suits leeks well
  • The dibbled-hole transplanting method is the key to long, white shanks
  • Trim roots and tops before transplanting to reduce transplant stress

Harvesting Leek

When ready: Stems are at least 2cm diameter (pencil-thick minimum, but 3-5cm is better). Can be harvested at any size from baby leeks (1cm diameter, 10 weeks) to full-size (5cm+, 5-6 months). No rush. Leeks hold well in the ground.

How to harvest: Loosen soil alongside the leek with a garden fork, then lever out. Do not pull straight up. The stem may snap. Trim roots and damaged outer leaves. Wash thoroughly between sheaths (soil and insects hide in the layers).

Where to next

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

Also worth sowing in the warm temperate zone this October: Lemongrass, Beetroot, Chilli Peppers and Cucumber.

The pest most likely to find your leek: Thrips (Onion, Tomato, Western Flower).

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Common Questions About Leek

When do you plant leek in Australia?

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

Does leek grow all year round in Sydney?

No. In the Warm Temperate zone the planting months are Jan to Nov. Outside that window it either bolts, sulks or gets cut down by the weather.

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 Warm Temperate zone, Sydney is its reference city.