How to grow Leek

At a glance

🌱 Grow your Leek with GardenDex

• Reminders to water it, timed to your weather and whether it's in a pot
• Frost and disease alerts for your garden, the night before
• Follow it from seed to harvest, and see what your garden grew in $
• Point your camera at any plant or bug to identify it

🗓️ When to plant

Start seeds indoors in late winter to early spring, or sow directly outdoors in mid-spring after the last frost. In mild climates, a late summer sowing produces winter harvests.

🌰 How to plant

1. Sow seeds indoors 8–10 weeks before your last spring frost, keeping soil warm and moist until germination.
2. Transplant seedlings outdoors in mid-spring when they're 15–20 cm (6–8 in) tall and pencil-thick.
3. Plant in a shallow trench or at soil level, spacing 15 cm (6 in) apart; as plants grow, gradually hill soil around the white stems to blanch them.
4. Alternatively, sow seeds directly outdoors in mid-spring and thin seedlings to proper spacing.

💧 Care

• Hill soil around stems every 3–4 weeks as plants grow to increase the white, tender portion and improve blanching.
• Keep soil consistently moist; mulch around plants to retain moisture and suppress weeds.
• Fertilize every 3–4 weeks with a balanced fertilizer or compost tea to support steady growth.
• Weed regularly to reduce competition, especially when plants are young.

🧺 Harvest

Begin harvesting when stems are 2–5 cm (1–2 in) in diameter, anytime from mid-summer onward, by loosening soil and pulling gently. Leeks improve in flavor after frost and store well in cool conditions for several months.

🐛 Common problems

Leek moth: Use row covers over young plants or apply organic spinosad spray if larvae appear in stems.

Rust (fungal disease): Improve air circulation, avoid overhead watering, and remove affected leaves; use a sulfur spray if needed.

Onion fly: Protect seedlings with row covers and keep garden free of onion debris.

🤝 Companion plants

💚 Good neighbours: Celery, Carrot, Beetroot, Chamomile

⚠️ Keep apart from: Beans, Peas

More vegetables guides