When to Plant Leek in Cairns — Tropical Guide

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.

Current Growing Conditions

Soil temperature: 25.2°C (optimal range: 13–24°C) ✗ Outside optimal range

How to Grow Leek in Tropical Australia

When to Plant

March to July (dry season). Leeks struggle in tropical heat and humidity. Short-season varieties only. Perpetual leeks are the most reliable option for FNQ.

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 win

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

Avoid planting near: Beans, Peas

Tropical Growing Tips for Leek

Recommended Varieties

  • King Richard (early, 75 days)
  • Perpetual Leek (perennial, division)

Key Challenges

  • Heat causing thin, tough stems
  • Purple blotch in humidity
  • Limited variety selection
  • Not enough cool weather for thick stems

Pro Tips

  • Perpetual leeks are the best option for tropical gardeners - divide clumps, harvest continually
  • King Richard matures in 75 days and can fit the dry season
  • Grow in afternoon shade to moderate temperatures

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).

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