Growing Leeks in Containers
Quick facts
Best choice for pots: baby leeks, though full-size leeks are possible
Container: large and deep, with drainage holes; around 40 cm across holds four or five full-size leeks
Compost: multi-purpose compost
Spacing: 10 cm for baby leeks, 15–20 cm for full-size
Watering: regular, all season, because pots dry out fast
Key moment: planting deep, even in a pot, for long white stems
Leeks are usually grown in the ground, but a deep pot on a patio or balcony can still give you a useful crop. It's also a good way round two common problems: poor, stony garden soil, and onion white rot, a soil disease that stops you growing leeks in the same bed for years. Fresh compost in a pot starts clean.
Baby leeks or full-size leeks?
Decide this first, because it changes the size of pot you need.
Baby leeks are the easiest option in containers. They're picked slim, about two months after sowing, so they need less depth and less feeding. You can fit plenty in one pot.
Full-size leeks take about six months and need a big, deep pot, steady watering and room to thicken. They're very doable, but expect fewer per pot than you'd get from the same space in the ground.
Choosing a container
Leeks grow a long stem underground, so depth matters more than width:
Go deep. The pot needs enough depth to plant each leek about 15 cm down, with plenty of compost below for the roots.
Size for full-size leeks: a pot around 40 cm across fits four or five.
Drainage: make sure there are holes in the bottom, and raise the pot on feet or bricks so water can run away in winter.
Skip standard grow bags. They're too shallow to plant leeks deeply, so the stems stay short and mostly green.
For more on choosing pots for vegetables, see growing vegetables in containers
Compost for container leeks
Fill the pot with multi-purpose compost. Leeks spend months in the same pot, so start with fresh compost rather than reusing an old mix. If the plants slow down in midsummer, a general liquid feed every so often helps keep them growing.
Sowing leeks in containers
You can sow leeks straight into their pot, which suits baby leeks well.
Fill the pot and water the compost.
Draw a shallow groove about 1.5 cm deep.
Sow the seed thinly along it and cover.
For baby leeks, thin the seedlings to about 10 cm apart once they're big enough to handle.
Sow from March to April, or into May and June for later baby leeks. For timings, see when to plant leeks in the UK
Planting young leeks into containers
For full-size leeks, it's better to raise seedlings in a tray or seedbed first, then move them into the big pot when they're about 20 cm tall and roughly as thick as a pencil.
Push a dibber or thick stick into the compost to make holes about 15 cm deep.
Space the holes 15–20 cm apart.
Trim the seedling roots to about 2.5 cm.
Drop one leek into each hole.
Fill each hole with water and leave it to settle. Don't press compost back in.
This is the same deep-planting method used in the ground. It's what gives container leeks a decent length of white stem.
Watering container leeks
A pot holds far less water than a garden bed, so container leeks need watering right through the season, not just in dry spells. Check the compost with a finger every few days in summer, and water whenever the top few centimetres feel dry. Water the compost, not the leaves, as wet foliage encourages leek rust.
For more detail, see how often to water leeks
Where to put container leeks
Stand the pot in a sunny spot, sheltered from strong wind. Leeks are hardy and cope with cool weather well, but a pot in full wind dries out quickly and can blow over as the plants get taller.
Protecting container leeks
Allium leaf miner and leek moth can damage leeks in pots just as easily as in the ground. Covering the pot with fine insect-proof mesh keeps them out. Slugs may also go for young plants after planting.
For other problems, see why leeks don't grow.
Container leeks in winter
Leeks themselves are hardy, but compost in a pot can freeze solid in a long cold spell, which makes the leeks hard to lift. Move pots against a sheltered wall for winter, and lift a few before a hard freeze is forecast.
Harvesting container leeks
Lift baby leeks once they're a size you want, usually about two months after sowing. Full-size leeks can be lifted from late summer onwards, taking a few at a time. Loosen the compost around each one with a hand fork and ease it out by the base.
For more detail, see when to harvest leeks. For the whole growing season, see how to grow leeks in the UK
Common questions
Can you grow leeks in pots?
Yes. Baby leeks are the easiest option, but full-size leeks also grow well in a large, deep pot of multi-purpose compost with regular watering.
How many leeks can you grow in a pot?
A pot around 40 cm across holds four or five full-size leeks spaced 15–20 cm apart. Baby leeks can go much closer, about 10 cm apart.
Can you grow leeks in grow bags?
Standard grow bags are too shallow for leeks. They need planting about 15 cm deep to form long white stems, so a deep pot works much better.
Do leeks in pots survive winter?
The leeks are hardy, but compost in a pot can freeze solid. Move pots to a sheltered spot and lift a few leeks before a long cold spell.
Container size, spacing, planting and watering based on RHS guidance.