GrowSabzHow to grow leek in pots
Also called porrum, allium, kurrath, poireau · Allium ampeloprasum var. porrum
لیک
- ☀️ Sunlight
- 6–8hours daily
- 💧 Water
- 1.3 Levery 3 days, 15 L pot
- 🌡️ Ideal temp
- 13–24°C
- 🪴 Min pot
- 15 L25 cm deep
- 🧺 Harvest
- 90–120days from sowing
- ⚖️ Yield
- 3 kgper 20 L pot
Leek gives you a window rather than a single harvest day. The first are ready around day 90, and you can keep pulling for roughly 60 days after that — lifting them as you need them rather than all at once. Left too long they get woody, so the window has an end.
Short answer
Grow leek in a 15 litre container at least 25 cm deep, watering about 700 ml per 10 litres of soil every 3 days, and keep temperatures between 13 and 24 °C. First harvest comes 90–120 days after sowing.
Where to plant it
What size pot does leek need?
15 litres and 25 cm deep is the realistic minimum for a single plant. Pick a container below to see what changes.
| Container | Minimum size | Depth | Notes |
|---|---|---|---|
| Pot | 15 L | 25 cm | Ensure good drainage and sufficient depth for root development. |
| Grow bag | 15 L | 25 cm | Fabric bags promote air pruning and good drainage. |
| Open ground | — | 30 cm | Plant in well-drained, fertile soil. Mound soil around stems for blanching. |
| Raised bed | 25 L | 30 cm | Ideal for deep root growth and easy blanching. |
Watering
How often should you water leek?
Every 3 days through the growing season, at about 700 ml per 10 litres of soil — daily in hot weather, every 5 days when it turns cool. Water in the early morning. Deep root watering works best.
Too little water
- wilting
- stunted growth
- tougher texture
Too much water
- yellowing leaves
- soft stem base
- stunted growth
Avoid: standing water; letting soil dry out completely.
Climate
Can you grow leek where you live?
No hardiness zone needed — compare your actual temperatures against the plant's own limits.
| Ideal range | 13 – 24 °C |
|---|---|
| Survives | -10 – 30 °C |
| Germinates above | 7 °C — best at 18 °C, about 10 days |
| Sunlight | 6–10 hrs/day, best 8 |
| Frost | Low sensitivity |
Timeline
Leek growing stages, day by day
Click any stage to see what's happening. Durations shift with temperature — a warm season runs roughly a quarter faster than a cool one.
Feeding
Fertiliser schedule for leek
Feed on the interval below, changing what you give as the plant shifts from making leaves to making fruit.
| Stage | What to use | Per 10 L | Every |
|---|
How to prepare each feed
Common mistakes
Why leek fails, and how to avoid it
- A container that is too small
Below 15 litres the root run is too shallow. The plant grows, flowers late, and drops whatever it sets because it cannot support the crop.
- Watering too lightly
A daily splash wets the top few centimetres and nothing else. Leek wants about 700 ml per 10 litres of soil — one deep soak beats three shallow ones.
- Planting it beside Beans
Legumes like beans and peas can stunt the growth of alliums, including leeks.
Companions
What to plant with leek
Good neighbours
Carrots help break up the soil, improving aeration and drainage which benefits leek roots.
Leeks and celery are good companions, sharing similar growing conditions and not competing for nutrients.
Leeks can help deter pests like onion thrips and cabbage loopers from brassicas.
Marigolds repel nematodes and other soil-borne pests, protecting leek roots.
Chamomile is believed to improve the growth and flavor of nearby plants, including leeks.
Keep apart from
Legumes like beans and peas can stunt the growth of alliums, including leeks.
Legumes like beans and peas can stunt the growth of alliums, including leeks.
Asparagus competes heavily for nutrients, especially in established beds, potentially hindering leek growth.
Some gardeners report that parsley can inhibit the growth of leeks when planted nearby.
Problems
Leek pests and diseases
Each lists the weather that brings it on, so you know when to start checking rather than reacting once it's established.
Leek Moth humidity any · temp mild (10-25)
Larvae tunnel into the leaves and shafts, causing damage, discoloration, and potential rot. Look for small holes and frass.
Onion Thrips humidity <60% · temp >25
Tiny, slender insects that suck sap from leaves, causing silvery streaks, distorted growth, and reduced vigor. Severe infestations can stunt plants.
Leek Rust humidity >80% · temp 10-20
Appears as small, raised orange-brown pustules on leaves. Can reduce photosynthesis and overall plant vigor, especially in humid conditions.
White Tip Disease humidity >90% · temp cool (5-15)
Caused by the fungus Phytophthora porri. Tips of leaves turn white and die back, often spreading downwards. Favors cool, wet conditions.
Downy Mildew humidity >90% · temp cool (10-20)
Pale yellow spots on leaves, often with a purplish-grey fuzzy growth on the underside. Can lead to leaf dieback and reduced yield.
Onion Maggot humidity any · temp cool to mild (10-20)
Larvae tunnel into the base of young leek plants, causing wilting, yellowing, and eventual death. Often seen in cool, moist soil.
Botrytis Leaf Blight humidity >85% · temp cool to mild (15-25)
Small, white, sunken lesions on leaves, often with a purple halo. Can cause leaf dieback and reduce plant vigor, especially with prolonged leaf wetness.
Harvest
When to harvest leek
First picking falls between day 90 and day 120, and the plant then keeps producing for about 60 days. Pick often — what you leave on the plant signals it to stop making more.
How to tell it's ready
- Shaft diameter is 1-2 inches (2.5-5 cm)
- Plant height is 12-18 inches (30-45 cm)
- White shaft is firm and well-blanched
How much to expect
Storing it: Store unwashed leeks in the crisper drawer of the refrigerator for up to 2 weeks. Trimmed leeks can be wrapped in a damp paper towel.
Questions
Leek: common questions
How long does leek take to grow?
About 120 days from sowing to the first harvest, with picking usually starting between day 90 and day 120. It then keeps producing for roughly 60 more days. Warm weather pulls that forward; cool weather pushes it back.
What size pot does leek need?
At least 15 litres and 25 cm deep for one plant. A raised bed wants 25 litres of soil and 30 cm of depth.
How often should I water leek?
About 700 ml per 10 litres of soil, every 3 days in normal weather — daily when it is hot and every 5 days when cool. Water in the early morning.
Why is my leek flowering but not fruiting?
Almost always pollination. Leek carries separate male and female flowers and needs pollen moved between them — without insects, nothing sets. Hand-pollinate in the morning with a male flower brushed against the centre of a female one.
What temperature does leek need?
It does best between 13 °C and 24 °C and survives from -10 °C to 30 °C. Seed needs soil above 7 °C to germinate, ideally around 18 °C.
Can I grow leek in winter?
It tolerates cold better than most, down to about -10 °C, so a sheltered spot or a cold frame will often carry it through.
How do I know when leek is ready to harvest?
Shaft diameter is 1-2 inches (2.5-5 cm); Plant height is 12-18 inches (30-45 cm); White shaft is firm and well-blanched. Once picked: store unwashed leeks in the crisper drawer of the refrigerator for up to 2 weeks. trimmed leeks can be wrapped in a damp paper towel.