How to Grow Leeks at Home in the UK

Leeks are one of the most rewarding crops a beginner can grow in the UK, and one of the most forgiving. They are tough, untroubled by frost, and they sit patiently in the ground waiting for you — there is no rush to harvest, no glut to deal with, and no race against the weather. Plant them in summer and you can be pulling sweet, mild leeks from October right through to the following spring.

This guide takes you from a packet of seed to a row of fat, white-stemmed leeks, with the real UK timings and the small handful of tricks (deep planting, a bit of earthing up) that make all the difference. It is genuinely doable in your first season.

Why grow leeks

Leeks earn their place in a beginner's plot for three solid reasons.

They are genuinely hardy. Leeks are members of the allium family — the same tribe as onions and garlic — but unlike onions, which you lift and store, leeks are happy to stay in the soil through the worst of a British winter. A hard frost doesn't bother them; in fact a touch of cold sweetens the flavour. You lift them as you need them, so a leek is effectively stored alive in the ground, fresh until the moment it reaches the kitchen.

They fill the hungry gap. The "hungry gap" is that lean stretch from late winter into early spring when last year's stored crops are running out and this year's sowings are barely up. It is the hardest part of the growing year for anyone trying to eat from their own plot. Leeks crop right through it. A late variety sown in spring will feed you in February and March, when there is little else to pull.

They stand all winter and ask for almost nothing. Once a leek is in the ground and established, it looks after itself. There is no daily watering in the rain of a UK autumn, no tricky support, no glut arriving all at once like courgettes. They simply stand there, thickening slowly, ready when you are. For a calm, low-stress crop that quietly extends your growing year by months, leeks are hard to beat — they sit comfortably alongside kale as a backbone of the winter plot.

Choosing varieties

Leek varieties are usually grouped by how early they mature, and a little planning here gives you leeks for a much longer stretch. The trick is to grow more than one type: an early for autumn, a maincrop for the heart of winter, and a late variety to carry you into spring.

Early varieties (autumn, roughly September to November). These grow fast and give you long, slender leeks before the worst weather arrives, but they are less frost-hardy and won't stand as long.

• King Richard — a quick, tall, mild leek with a long white shaft. Excellent for autumn, but lift it before deep winter as it isn't fully hardy.
• Zermatt — a neat, baby-friendly early leek, good if you like to harvest small and tender.

Maincrop varieties (winter, roughly December to February). These are the classic stout, hardy leeks that form the backbone of the crop.

• Musselburgh — the dependable beginner's leek. An old Scottish variety, thick, hardy and reliable, it will stand through frost and snow without complaint. If you grow only one leek, grow this.

Late varieties (late winter into spring, roughly February to April). The toughest of the lot, bred to hold in the ground when everything else has gone over.

• Bandit — superbly hardy, holds its quality late, and shrugs off the worst of the cold. Ideal for filling that hungry gap.
• Apollo — vigorous and rust-resistant, a good choice if rust has troubled your leeks before (more on that below).

Where to grow

Leeks are not fussy, but a little thought about position pays off in fatter stems.

Sun. Give leeks an open, sunny spot. They will tolerate light shade, but they grow sturdiest in full sun. They are upright plants that take up little ground area, so they slot neatly into gaps and along the edges of a bed.

Soil. Leeks like a fertile, moisture-retentive but free-draining soil — a rich, crumbly loam is ideal. They are hungry plants that grow over a long season, so dig in plenty of well-rotted compost or manure before planting, or simply grow them in a bed you've been improving with mulch over time. If you garden the no-dig way, a good layer of compost on the surface does the same job. Light, sandy soils dry out too fast for the best stems unless you keep the water up; heavy clay is fine as long as it isn't waterlogged in winter. For more on getting your ground right, see improving your soil.

Rotation. Because leeks are alliums, follow the same crop-rotation rule you would for onions and garlic: don't grow them where any allium grew the year before. Moving the allium bed around the plot each year helps avoid the soil-borne diseases that build up where the same family is grown repeatedly — the most serious being onion white rot. Plan it with the crop rotation planner if you find it hard to keep track. Leeks are a classic crop to follow on from early potatoes or peas, slotting into ground that's just been cleared in summer.

Sowing and raising seedlings

Leeks are grown from seed, and they are slow to start — this is normal. The seed is sown in spring and the young plants are grown on for a few months before being moved to their final home. You have two simple ways to raise them.

Method 1: a seedbed. This is the traditional approach. Sow thinly into a short row in a corner of the plot or a spare patch of fine, raked soil with a good tilth. Sow from late February (under cover) through to April, about 1cm deep. Keep the row weeded and watered. The seedlings come up looking like fine blades of grass and slowly thicken into little upright plants. When they are about the thickness of a pencil and 15–20cm tall — usually June or July — they are ready to lift and transplant.

Method 2: modules. If you don't have spare ground, or you want neater control, sow into module trays or small pots of multipurpose compost. Sow a few seeds per cell and thin to the strongest, or sow a small pinch and plant out the resulting clump together. Modules are tidy and avoid the root disturbance of lifting from a seedbed. This is a good route if you're growing on a patio or short of space, much like raising other transplants for container growing.

Either way, the principle is the same: sow in spring, grow the young plants on until they're pencil-thick, then transplant in early summer. Don't be tempted to rush — undersized seedlings transplant poorly, while a sturdy pencil-thick plant establishes fast.

Transplanting

This is the step that makes a leek a leek, and it is delightfully simple once you've seen it done. The aim is to plant each seedling deep into a hole so that a good length of stem is buried — and buried stem becomes the long, white, tender shaft you're after.

Here is the classic dibber-hole-and-puddle method:

1. Lift your seedlings. If they're in a seedbed, ease them up with a fork and gently tease them apart. Shake off the soil so you can see the roots.
2. Trim, if you like. Many growers snip the roots back to about 2–3cm and trim the very tips of the leaves by a third. This isn't essential, but it makes the seedlings easier to drop into the holes and reduces water loss while they re-root. (Skip the root trim if you prefer — leeks are forgiving.)
3. Make a dibber hole. Using a dibber, a thick stick, or the handle of a trowel, push a hole about 15cm deep into prepared soil. Space the holes about 15cm apart, with 30cm between rows. For very fat leeks, space them a little wider; for slimmer ones, closer.
4. Drop the seedling in. Lower one seedling into each hole so it sits at the bottom. Don't backfill the hole with soil — leave it open. This is the part that surprises beginners: the leek sits in an open hole, with just its leaves poking out the top.
5. Puddle it in. Fill the hole to the brim with water from a watering can. The water washes just enough soil down over the roots to settle the plant, while leaving the rest of the hole as an air pocket that gradually fills as the leek grows and thickens. That swelling within a loose hole gives you a long, clean white shaft.

That's it — no firming, no backfilling. The hole does the work. Within a week or two the seedlings perk up and start growing away. Water again in dry spells while they establish.

Blanching for long white stems

The pale, mild lower portion of a leek is the prize, and the technique for producing it is called blanching — excluding light from the stem so it stays white and tender rather than turning green and tougher. The deep dibber hole at transplanting does most of this work for you. But you can add to the length of white stem as the leeks grow by gradually drawing soil up around them — a process gardeners call earthing up, the same idea you'll know from growing potatoes.

To earth up leeks, simply draw dry soil up around the stems with a hoe two or three times as the season goes on, building it into a low ridge. Each time you cover a little more stem, you blanch a little more of it white. A couple of cautions:

• Earth up in stages, not all at once. Add a few centimetres at a time so you don't bury the growing point or smother the plant.
• Keep soil out of the leaf joints. Try not to let loose earth fall down into the centre of the leek where the leaves fan out — grit trapped between the layers is a nuisance to wash out in the kitchen. Earthing up on a dry day, and only up the solid stem, helps.

Some growers slip a cardboard collar or a length of pipe around each stem instead of using soil — it keeps the blanched section grit-free. For most beginners, though, deep planting plus a little earthing up gives perfectly good long white stems with no extra kit.

Care

One of the joys of leeks is how little they ask once they're in. A few simple jobs keep them growing steadily.

Watering. Leeks need steady moisture, especially in their first weeks after transplanting and during any dry summer spells, when a good soak every week or so keeps them swelling. Once autumn arrives and the rain sets in, you can usually leave them to the weather. Don't let young transplants bake dry, but equally don't drown established plants in winter — soil that stays waterlogged can rot the bases.

Weeding. Keep the row weed-free, particularly while the leeks are small and easily out-competed. Hoe carefully between the plants — leek roots are shallow, so a light touch is best — or hand-weed close to the stems. A mulch of compost between the rows smothers weeds and locks in moisture, doing two jobs at once.

Feeding. If you prepared the bed well with compost or manure, leeks rarely need extra feeding. On poorer soil, a watering with a general-purpose liquid feed in mid-summer gives them a boost while they bulk up, but go easy — over-feeding produces soft growth that's more prone to disease.

Rust and leek moth

Leeks are healthy crops, but two problems are worth knowing about so you can spot and manage them early.

Leek rust is the most common. It shows as bright orange, powdery streaks and pustules on the leaves, usually appearing in damp summers or where plants are crowded. Mild rust is mostly cosmetic — the leeks are still perfectly edible, you simply peel off the worst leaves. To reduce it: space plants well so air moves freely, don't over-feed with nitrogen, rotate your allium bed each year, and choose a resistant variety such as Apollo if rust is a regular visitor. Badly affected leaves can be removed and binned (not composted).

Leek moth is a smaller but growing problem, more common in southern England. The caterpillars tunnel into the leaves and stems, leaving whitish blotches and damaged centres. The simplest defence is to grow your leeks under a fine insect-proof mesh from planting out, which keeps the egg-laying moths off altogether — the same approach that protects brassicas from cabbage white caterpillars. Removing and destroying affected plant material also helps break the cycle. For most gardeners, leek moth is an occasional nuisance rather than a crop-wrecker.

Harvesting through winter

This is the easy part — and the part that makes leeks so useful. You harvest leeks simply by lifting them as you want them, right through autumn and winter. There's no need to clear the whole row at once; leave them standing and lift one or two at a time, fresh for each meal.

Don't pull leeks straight up by the leaves — the stem will likely snap and you'll be left holding the top. Instead, loosen the root with a fork pushed in alongside the plant, then lift it cleanly. Trim off the roots and the coarse upper leaves, and you're left with that prized white-and-pale-green shaft.

Start with your early varieties in autumn, move on to maincrop Musselburgh through the depths of winter, and finish with late varieties such as Bandit and Apollo in February and March. Sequenced like that, a single sowing year can give you fresh leeks for six months or more.

A few harvest notes:

• Lift in frost. Even frozen ground is no barrier — leeks are unharmed by frost, though if the soil is rock-solid you may need to wait for a thaw to fork them out.
• They don't store well lifted. Unlike onions, leeks are best left in the ground until needed. Once lifted, use them within a week or so, or chop and freeze the surplus.
• Clear before they bolt. Come spring, leeks left too long will start to send up a tough flower stem (they "bolt"). Lift any remaining leeks by April before this happens — or leave one to flower, as the globe is loved by bees.

Once you've got the rhythm — sow in spring, plant deep in summer, lift all winter — leeks become one of those quietly dependable crops you'll grow every single year.

Once you've caught the leek bug, the rest of the allium family is well worth a try — they share the same easy rotation and most of the same care. Have a look at growing onions for summer harvests and storing, and garlic, which you plant in autumn and lift the following summer. Pair them with hardy kale and you'll have a winter plot that keeps feeding you long after the rest of the garden has gone to sleep. Browse more crops over on the grow vegetables hub.