How to grow leek in Australia 🧅

Leeks grow well in most conditions. The aim is to start them early enough that they reach a useful size before the worst heat or cold of the year, but they tolerate both extremes reasonably well.

Leeks are usually grown from seedlings, though seeds work too if you have time for the longer growing period.

Spacing: 15–20cm between plants in rows 30cm apart. Crowded leeks produce thin stems.

Depth and the trench method: Leeks benefit from being planted in trenches and progressively earthed up as they grow. This blanches the lower portion of the stem white — the part you actually want for cooking. The simplest method: dig a 15–20cm deep trench, drop seedlings into the trench at the right spacing, fill with just enough soil to cover the roots. As the plants grow, gradually fill in the trench with soil so the lower 10–15cm of stem stays buried. By harvest time, you've got long white stems rather than green ones.

A simpler approach: use a dibber (or a thick stick) to make holes 15cm deep, drop a seedling in each hole, and fill the hole with water rather than soil. The soil falls in over time and naturally earths up the plant. Less work, similar result.

Soil: Rich, well-drained soil with plenty of organic matter. Leeks are heavy feeders over a long period — top up with compost or pelleted manure mid-season.

Leeks adapt well to all three.

In-ground is the standard. The trench method works easily in open beds.

Raised beds suit leeks very well — improved drainage and soil quality control help. The depth of a raised bed makes the trench-and-earth-up method easier.

Pots can produce leeks but the white stem ends up shorter because there's less depth for earthing up. A 30cm deep pot supports 4–6 leeks. Use the dibber-and-water method rather than trench planting in pots. Yields are modest compared to in-ground but the leeks are still usable.

Full sun to part shade — 4 to 8 hours daily. Leeks tolerate more shade than most vegetables and will produce in partly shaded spots, though stems will be slightly thinner.

Water consistently. Leeks have shallow roots and dry out quickly in warm weather. Mulch heavily.

Leeks are ready when the stems are at least 2cm thick — usually 5–7 months from planting. Larger leeks (4cm+) take another month or two but the trade-off is worth it for substantial cooking stems.

Harvest by digging carefully with a fork and lifting the whole plant — pulling from the stem breaks it.

Unlike onions and garlic, leeks don't need curing. They can be eaten within hours of harvest or stored in the fridge for 1–2 weeks. They can also be left in the ground for weeks of additional storage — a major advantage in cool climates where harvest can be staggered through winter.

Rust can affect leek leaves in humid climates. Same as garlic rust — remove affected leaves, improve airflow, don't water from overhead.

Leek moth larvae burrow into stems causing soft rot. Rare in Australian home gardens. Net plants if you've had problems previously.

Thrips cause silver streaking on leaves. Treat with insecticidal soap if damage is significant.

White rot — same fungal disease as garlic and onion. Rotate crops, never plant alliums in the same bed more than once every four years.

Plant near: Carrots (mutual pest deterrence), celery, brassicas.

Keep away from: Peas and beans (alliums inhibit legume nitrogen fixing).

Welsh Wonder — Reliable, large-stemmed variety widely available in Australia. Suits all climates.

Bulgarian Giant — Very long white stems, productive. Excellent for cool temperate climates.

King Richard — Faster-maturing variety (around 75 days). Suits gardeners who want quicker harvest, particularly useful in subtropical zones where the cool season is shorter.

Musselburgh — Heritage Scottish variety, hardy, good for cool/cold climates. Excellent flavour. Heritage seed suppliers.

Giant Carentan — Long-season heritage variety with mild sweet flavour. Suits all climates with a long enough growing window.