How to grow Leek in Australia
Leeks are a mild, versatile member of the onion family, grown for their long white stems. They are easy, hardy and slow, and they do not all have to be picked at once: they stand in the ground for weeks and can be dug as you need them. Plant seedlings deep, or earth them up, for long white shanks.
📖 Our full guide: How to Grow Leek in Australia
At a glance
When to sow by region
| Region | When to sow | Regional note |
|---|---|---|
| South East Queensland | March to July | |
| Northern Rivers NSW | March to July | |
| Sydney & Coastal NSW | March to August | Long cool-season window; July plantings mature through winter. |
| Melbourne & Victoria | March to August | Sow from March to August and transplant in spring or early summer. Leeks are frost hardy and grow on steadily through the Melbourne winter. |
| Adelaide & SA | March to July | |
| Perth & WA | February to May | Sow trays Feb to May in bright shade, transplant pencil thick seedlings Apr to Jun. Grows steadily through the mild winter. |
| Tasmania | August to November | Sow Aug to Nov, transplant pencil-thick seedlings in summer, harvest all winter. A Tasmanian staple. |
| Canberra & ACT | September to January | Sow Sep to Jan, transplant pencil thick seedlings. Fully frost hardy; stands in the ground all winter. |
| North Queensland | May to July | Dry season May to Jul. Leek needs cool temps; sow early in dry season. |
| Darwin & Top End | May to July | Dry season May to Jul. Leek needs cool temps; sow early in dry season. |
Not to be confused with: Spring Onion, which is harvested young and slim, and Onion, grown for its bulb.
Where to plant
Leeks prefer an open, sunny position and grow best in reasonably good, friable soil rich in organic matter. Dig in compost before planting, but do not add fresh manure at planting time. The soil should hold moisture but drain well.
Rotate leeks with other crops and do not plant them where onions, garlic or leeks grew recently, which helps keep rust and other onion-family diseases down.
- South East Queensland and the Northern Rivers: sow from March to July.
- Sydney: sow from March to August. July plantings mature through winter.
- Melbourne and Adelaide: sow from March to August and transplant from autumn to spring. Leeks grow steadily through winter.
- Perth: sow in trays from February to May in bright shade, and transplant pencil-thick seedlings from April to June.
- Canberra: sow from September to January and transplant pencil-thick seedlings. Leeks stand in the ground all winter.
- Hobart: sow from August to November, transplant in summer and harvest all winter. A Tasmanian staple.
- North Queensland and Darwin: sow early in the dry season, May to July.
How to plant
- Sow seed in trays or a seedbed, or buy seedlings, which saves four to six weeks of growing time.
- Transplant when seedlings are about 20 cm tall and pencil thick.
- Make holes about 15 cm deep with a thick stick or dibber, 10 to 15 cm apart, in rows about 30 cm apart. Drop one seedling into each hole and fill the hole with water rather than soil; the soil settles around the roots and the stem blanches in the hole. Or lay seedlings in a trench and backfill; they stand up on their own.
- Water in gently.
- Plant small batches every few weeks for a steady supply.
Watering and feeding
Keep leeks well watered and weeded throughout the season. Dry spells give tough, small stems. Mulch to hold moisture.
Feed with a balanced or nitrogen-rich liquid fertiliser every few weeks while they grow, and dig in compost before planting.
Pruning and care through the year
- As the stems thicken, draw soil or mulch up around them to lengthen the white part. Keep soil out of the centre of the leaves.
- Weed carefully, as leeks compete poorly with weeds.
- Remove leaves with heavy rust and clear old plants at the end of the season.
Harvesting
Leeks can be harvested young, about the size of a spring onion, or left to grow fat and large. From seedlings, expect a crop in about three to four months. Loosen the soil beside each leek with a fork and lift it; pulling often snaps the stem. Hardy leeks can stand in the ground for weeks, so dig them as you need them.
Trim the roots and the top of the leaves, wash out any soil between the layers, and keep them in the fridge for a week or two.
Growing in pots
Leeks grow in a pot at least 30 cm deep, which allows deep planting. Use a quality potting mix, plant seedlings 10 cm apart, and water and feed regularly. Baby leeks are the best choice for pots.
Using it
Slice leeks into soups such as potato and leek, braise them, add them to pies, quiches and stews, or cook them slowly in butter. Use the white and pale green parts; the dark green tops are good for stock.
Companion planting
Leeks are slim and upright, so they fit between other cool-season crops.
Good companions
- Carrot A cool-season root crop that grows at the same pace and shares the same well-dug soil. The two are traditionally grown together.
- Celery Likes the same rich, moist soil and steady water through the cool months.
Keep apart
Avoid planting these close to leek.
- Legumes Members of the onion family are traditionally kept away from beans and peas, which are said to grow poorly beside them. The evidence is thin, but it is easy to give them separate beds.
Pests and diseases
Leeks are fairly resilient. Rust is the most common problem.
Pests to watch for
- Thrips Silvery, speckled streaks on the leaves in warm, dry weather. Hose plants down and keep them watered.
- Snails Chewed, messy foliage, especially on young plants.
Diseases to watch for
- Rust Bright orange pustules on the leaves, worst in humid weather and on crowded or poorly fed plants. Remove the worst leaves; the stems are still edible. Choose rust-resistant varieties if it recurs.
- Leaf blight Pale or brown, dying patches on the leaf tips and leaves in wet weather. Space plants for air flow and remove affected leaves.
Common questions
How do I get long white leeks?
Plant seedlings deep, in holes about 15 cm deep, and fill the holes with water rather than soil. As the stems thicken, draw soil or mulch up around them. The part kept out of the light stays white.
When should I plant leeks in Australia?
In autumn and winter in most regions: March to July in south east Queensland, March to August in Sydney, Melbourne and Adelaide, and February to May in Perth trays. Canberra and Hobart sow in spring, and the tropics early in the dry season.
How long do leeks take to grow?
About three to four months from seedlings, longer from seed. You can pick them young like spring onions or let them grow large.
Can leeks stay in the ground?
Yes. Leeks are frost hardy and stand in the ground for weeks, so you can dig them as needed through winter.
What are the orange spots on my leeks?
Leek rust. Remove the worst leaves, keep plants well fed and spaced, and rotate the bed. The stems are still fine to eat. Grow rust-resistant varieties if it keeps coming back.
Can I grow leeks from seedlings?
Yes, and it saves four to six weeks. Wash the soil off the roots, plant them deep, 10 to 15 cm apart, and water them in gently.
Sources we checked: Gardening Australia: Top tip, growing leeks; RHS: Leeks, grow your own.