How to Grow Leeks in the UK

Leeks are one of the most reliable winter veg you can grow in the UK. They stand through hard frost, shrug off snow and keep giving you fresh stems when the rest of the plot is bare. Sow a row in February, plant it out in June, and you’ll be picking from autumn right through to spring.

They’re forgiving of poor soil, cope with a bit of shade and need less fuss than onions or garlic. Planting them is fun too: you just drop the seedlings into deep holes and water them in. If you’re starting a vegetable garden for the first time, leeks are a great confidence builder. Here’s everything from sowing to supper.

What are the best leek varieties for the UK?

Your variety decides when you’ll be picking. Leeks come in early, mid-season and late types. Grow one of each and you can harvest from September to April.

Early varieties (September to November)

• King Richard: quick-growing, with long, slim stems. Ready from September. Mild and lovely in salads and stir-fries. Less hardy than later kinds, so eat it before the hardest frosts.
• Carlton F1: a reliable early hybrid with smooth, even stems. Ready September to November, and slow to bolt from early sowings.

Mid-season varieties (November to February)

• Musselburgh: the classic old Scottish leek. Thick, sturdy stems with a mild, sweet taste. Very hardy and happy in most soils. The best all-rounder for beginners.
• Bleu de Solaise: a French heirloom with blue-green leaves that turn violet in the cold. It looks fantastic in the winter plot and tastes great. Ready December to March.

Bleu de Solaise turns violet in the cold and looks great on a winter plot. Leeks stand happily in frosty ground until you need them.

Late varieties (January to April)

• Bandit: a late leek built for hard winters. Very thick, dark green stems and good rust resistance. It stands until April without bolting. A great pick for northern gardens.
• Apollo F1: a vigorous late leek with tall, even stems. Very hardy, with good rust resistance, and it stays in good shape in the ground for months.

Variety comparison table

Gardener’s tip: For leeks all winter, sow King Richard for early eating and Bandit for late winter. Between them, they cover September to April.

How to sow leeks in modules

Modules give leeks the best start. The little seedlings are safe from slugs, cold and weeds, and you can start earlier.

When to sow

Sow indoors from late January to March. February suits most gardens. That gives them a few months to grow before planting out in May or June. Sowings in March or April still work, but the leeks will be a bit smaller.

Sowing method

Fill module trays with seed compost or fine multi-purpose compost. Sow 2-3 seeds per cell, 1cm deep, and water gently. Stand them on a cool windowsill, in an unheated greenhouse or in a cold frame. They usually take a couple of weeks or more to come up. Leeks like it cool, so skip the heated propagator.

The seedlings look like fine blades of grass. Keep them in good light and water when the compost dries on top. No need to thin them. They’ll grow happily together and you’ll separate them when you plant out.

There’s no need to thin them. Let them grow on together and separate them when you plant out.

Hardening off

From late April, put the trays outside by day and bring them in at night for a week or so. This toughens them up. By planting time they should be about as thick as a pencil and 15-20cm tall.

How to transplant leeks: the dibber method

The dibber method is the traditional way to plant leeks, and it works a treat. The stems start blanching underground from day one, which gives you those long white shanks.

Preparing the bed

Pick a sunny or partly shaded spot with reasonable soil that drains well. Leeks aren’t fussy. If the bed had compost or manure for an earlier crop, that’s plenty. On poor or packed-down ground, dig in some well-rotted compost a few weeks before planting.

Transplanting step by step

1. Water the module tray well an hour before. The seedlings come out more easily.
2. Make holes with a dibber, a thick piece of dowel or an old spade handle. Make each one 15cm deep, 15cm apart, with 30cm between rows.
3. Ease out the seedlings and gently tease apart any that are growing together. Trim the roots to about 3-4cm and the leaves to about 15cm.
4. Drop one seedling into each hole so the roots touch the bottom. It’ll look tiny and lost. That’s exactly right.
5. Fill each hole with water from a can with a fine rose. Don’t push soil back in. The water washes a little soil over the roots, and the stem fills the hole as it grows.

Fill each hole with water and leave it open. The water settles soil round the roots and the stem stays clean as it grows.

Why you must not backfill

Pushing soil back in traps grit between the leaves as the leek grows, and you’ll spend ages washing them. Leaving the hole open keeps the stem clean. Rain and watering settle the soil around the roots in their own time.

Spacing options

Baby leeks are handy if space is tight. They’re ready sooner, suit stir-fries and salads, and you can fit lots into a raised bed.

How to earth up leeks for longer white stems

Earthing up just means drawing soil up around the stems as they grow. It keeps light off the lower stem, so more of it stays white and tender.

When to start

Start in late July or August, once the stems are at least 2cm thick. Don’t start too early, as thin young stems can rot if buried.

How to earth up

Draw soil up around the stems with a hoe or rake, a few centimetres at a time. Try not to drop soil between the leaves. Some growers slip a cardboard tube or a bit of drainpipe over each stem to keep soil out. Repeat every 3-4 weeks through autumn.

Or plant them in a trench. Dig it 15cm deep, plant in the bottom and fill it in gradually as they grow. Same result, less effort.

Gardener’s tip: Slide a cardboard toilet roll tube over each seedling at planting time. As you earth up, it keeps soil out of the leaves, so your leeks need less washing.

Draw soil up a few centimetres at a time, every three or four weeks. Keeping it out of the leaf joints saves a lot of washing later.

Feeding, watering, and aftercare

Leeks aren’t demanding. Once they’ve settled in, they need little help.

Watering matters most for the first couple of weeks after planting and in dry summer spells. Give a good soak once a week rather than a sprinkle every day. Established leeks cope with dry weather, but steady moisture gives thicker stems. Water less in autumn as growth slows.

Feeding is simple. If the soil had compost, you rarely need more. On poorer soil, scatter a general granular fertiliser in June or July, or give a general liquid feed every couple of weeks through summer. Stop feeding by September.

Weeding matters while they’re small, as leeks grow slowly at first and weeds can swamp them. Hoe carefully between rows with the blade shallow, and hand-weed close to the stems. By autumn their leaves shade out most weeds.

Month-by-month leek growing calendar

Pests and diseases

Leeks have fewer problems than most onion relatives, but two are worth knowing about.

Leek rust

Leek rust is the most common leek disease in the UK. You’ll see orange spots and pustules on the leaves, usually from late summer, especially in warm, damp weather. Mild cases are just cosmetic. Peel off the spotty outer leaves and the leek is fine to eat.

Bad cases weaken the plant and give thinner stems. To keep it down:

• Give plants their full 15cm spacing so air can move
• Don’t feed with lots of nitrogen after August
• Remove and bin badly affected leaves
• Grow resistant kinds such as Bandit and Apollo F1
• Move leeks to a new bed each year

Our guide to leek rust covers it in more detail.

Mild rust is mostly cosmetic. Peel off the spotty outer leaves and the leek underneath is fine to eat.

Allium leaf miner

Allium leaf miner is a pest that’s become more common across England and Wales. The adult fly leaves rows of tiny white dots on the leaves, then lays eggs. The grubs tunnel down the leaves into the stem, leaving brown lines, twisted growth and rot.

It’s busy twice a year: March to April and October to November. The best defence is covering your leeks with very fine insect mesh at those times. There’s no spray for home gardeners. Check plants often and destroy any with tunnels.

Cover leeks with fine mesh in March to April and October to November, when the fly is about. It’s the best defence for home gardeners.

Other problems

• Slugs go for young transplants. Use a few wildlife-friendly slug pellets, beer traps or evening torch patrols in the first few weeks
• White tip is a fungus that turns leaf tips white and papery. It’s mostly cosmetic. Good drainage and air flow help
• Bolting is when a leek sends up a flower stalk. It’s usually set off by a cold snap then warm weather in spring. Pick bolting leeks straight away, as the stem soon turns woody

Five common mistakes when growing leeks

Backfilling the dibber holes

The most common mistake. Pushing soil back in traps grit in the leaves, and cleaning them becomes a chore. Water the holes and leave them open.

Transplanting too late

Leeks planted out after mid-July end up thin and short by winter. Aim to have them all in by the end of June, mid-July at the latest.

Forgetting to earth up

Without earthing up, you get a short white stem and a long green top. The green is edible but tougher and stronger. Even two or three sessions of drawing up soil makes a big difference.

Overfeeding with nitrogen

Rich feeds late in the season make soft, lush growth that’s more prone to leek rust and frost damage. Go easy and stop by September. In well-composted soil, leeks rarely need any extra feed.

Not using crop rotation

Growing leeks, or any onion family crop, in the same spot every year lets diseases build up. White rot, in particular, stays in the soil for many years. Move leeks each year and wait at least three years before going back to the same spot.

Harvesting leeks

Start picking once the stems are about 2cm thick. There’s no rush. Leeks don’t spoil in the ground, and frost, snow and freezing rain don’t bother them.

When to harvest each type

• Early kinds (King Richard, Carlton F1): September to November
• Mid-season kinds (Musselburgh, Bleu de Solaise): November to February
• Late kinds (Bandit, Apollo F1): January to April

How to lift leeks

Push a fork into the soil 10cm from the stem and lever the leek out gently. Don’t yank it up by the leaves, or it’ll often snap and leave the base behind. Shake off the soil and trim the roots.

Dig them as you need them. The ground is a better store than the fridge. Once lifted, they keep for about a week in the fridge wrapped in a damp cloth.

Ease leeks out with a fork rather than pulling on the leaves. The ground is the best store, so lift just what you need.

Clearing the bed

Lift any left by late March or early April. As spring warms up, leeks start to bolt and the middle turns woody. If you’ve got more than you can eat, slice and freeze them for soups and stews.

Growing leeks in containers

Leeks are happy in pots, so they suit patios, balconies and small gardens. Pick a pot or trough at least 30cm deep for the long roots and some earthing up. Fill with multi-purpose compost mixed with a handful of perlite.

Plant seedlings 10cm apart using the dibber method, with holes 10-12cm deep. Water often in summer, as pots dry out fast. Give a balanced liquid feed every two weeks from June to August.

Compact kinds like King Richard and Jolant are best for pots. You won’t grow show-sized leeks in a container, but slim stems from close planting are tender and tasty.

Leeks in the kitchen

The white and pale green parts are the mildest and most tender. The dark green tops are tougher but great for stocks and soups.

To clean them, trim the root and tough outer leaves. Slice lengthways and rinse under the cold tap, fanning the layers to wash out any soil.

British classics include leek and potato soup, cheese and leek pie and leeks in white sauce. They’re lovely roasted too: halve them lengthways, brush with oil and roast at 200C for 25-30 minutes. The RHS guide to growing leeks has more on varieties.

Now you’ve got leeks sorted, use our UK vegetable planting calendar to plan what to sow alongside them and keep your plot busy all year.

Frequently asked questions

When should I sow leeks in the UK?

Sow leek seed indoors in February or March. Sow 2-3 seeds per module, 1cm deep, in seed compost. They take a couple of weeks or more to come up. Plant out from May to July once they’re as thick as a pencil. In mild southern areas, you can also sow outside from March.

How do you transplant leeks using the dibber method?

Make a 15cm-deep hole with a dibber or stick. Drop one trimmed seedling in so the roots touch the bottom. Water the hole gently and don’t push any soil back in. The water settles soil around the roots, and the stem fills the hole as it grows, giving you a long white shank.

How far apart should I plant leeks?

Plant them 15cm apart in rows 30cm apart. That gives each leek room to grow a thick stem. For baby leeks, plant them just 5cm apart. You’ll get thinner stems, perfect for stir-fries and salads.

Do leeks survive frost in the UK?

Yes, leeks are very frost-hardy. They stand in the ground right through a British winter and are one of the few fresh veg you can pick from December to March. Dig them as you need them rather than all at once.

What causes orange spots on leek leaves?

Orange or rusty spots mean leek rust, a fungal disease. It’s common in warm, damp weather from late summer. Mild cases don’t affect eating, so just peel off the worst outer leaves. Give plants more space for air to move, and try a rust-resistant variety such as Bandit.

What is allium leaf miner and how do I prevent it?

It’s a small fly whose grubs tunnel into leek stems. It’s busy twice a year in the UK, in March to April and October to November. Cover your leeks with very fine insect mesh at those times. There’s no spray for home gardeners, so check plants and destroy any that show tunnelling.

Can I grow leeks in containers?

Yes, in a pot at least 30cm deep. Use multi-purpose compost and plant seedlings 10cm apart. Water regularly, as pots dry out fast. Choose a compact variety such as Jolant or King Richard, and give a liquid feed from June onwards.