Quick answer

The answer to when to plant garlic in the UK is a window rather than a date: mid-October to late November in most gardens, once the soil has cooled and stopped holding water. September is usually a fortnight or two early. On heavy wet ground, start cloves in modules and plant them out in spring.

Table of contents

Garlic is the crop where the calendar and the search traffic disagree. Interest peaks in early September, while most UK growers are six to ten weeks off planting.

What to check before a clove goes in

A date gets you within a few weeks. These four checks settle it, and each takes two minutes with a fork.

Soil warmth at clove depth

Garlic sits shallow, so the temperature that counts is only a few centimetres down. Scrape the top 5cm back and lay the back of your hand flat on the soil underneath.

In September it usually still feels neutral, close to your own skin, and that says wait. Once it makes your fingers ache within seconds you are near 10C, cold enough for cloves to root steadily rather than race into leaf. A bed against a south-facing wall holds its warmth a fortnight longer than an open one, so plant the cold corners first.

How the ground works, and where water sits

Turn one spit over. Soil that lifts in crumbs and shatters when tapped is ready; soil that comes up in glossy slabs holding the shape of the tines is too wet, and a clove pressed into that rots in an airless pocket.

Walk the plot after heavy rain too: water still standing two hours later means raised ridges, grit, or containers.

First frosts and what the beds are doing

The first air frost is the traditional cue and still a good one. Runner beans go limp overnight, dahlia foliage blackens, and the ground beneath follows within a week or two. Weeds are the other tell: while chickweed still germinates within days the soil is warm, and when seedlings stall the warmth has gone.

What the bed grew last

Garlic should not follow onions, shallots, leeks or garlic: white rot persists in the soil for years and rust carries over on allium debris, so a three to four year gap between allium crops is the cheapest disease control there is. A bed just finished with potatoes or beans is ideal. Skip ground given fresh manure, since surplus nitrogen buys leaf at the expense of the bulb.

Hardneck, softneck and elephant garlic

What you bought changes the timing more than anything else here, and the label almost always says which type it is.

Softneck

Softnecks have pliable stems that can be plaited and they are the UK mainstay. Solent Wight is the best known, bred on the Isle of Wight and able to store into the following summer, with Iberian Wight and Picardy Wight alongside it. They tolerate a wider window than hardnecks, though Early Purple Wight wants planting on time: a harvest from late May needs the autumn start.

Hardneck

Hardnecks throw a stiff central stem and, in early summer, a curling scape worth snapping off and cooking so the plant feeds the bulb instead. Lautrec Wight is the usual UK example: better flavour, fewer and fatter cloves, but keeping for months rather than a year. Being the more cold-hungry group, they want an autumn planting.

Elephant garlic

Elephant garlic is not garlic but a close relative of the leek, which is why the cloves are enormous and the flavour mild. Plant it in autumn, tip about 5cm down and 25 to 30cm each way. It is the most forgiving of an early start, so if you are itching to plant in late September, plant this.

Month by month, September to March

These dates assume an average year in the middle of England. Mild coastal and south-western gardens run later because the soil stays warm, northern Scotland earlier, and any year can shift the lot by a fortnight. Lean on the month, decide on the soil.

September

Nothing goes in yet across most of the country, and that is the right answer rather than a disappointing one. September ground still carries summer warmth, so cloves put in now push top growth the first hard frost knocks back. Order seed garlic before the good varieties sell out, and prepare the bed.

October

The window opens. Across most of England and Wales the second half of the month is when soil temperature, moisture and workability line up, and if the checks pass, that is when I would plant. Scotland and the north are usually ready a fortnight sooner.

November

The main planting month for most gardens, and the safe recovery if October slipped past. Cloves going in now finish only a week or two behind an October start. This is also when heavy soil decides for you: if the plot squelches underfoot, fill a module tray instead.

December and January

Garlic still goes in whenever the ground is workable and not frozen, and the cold requirement is comfortably met, though December bulbs run smaller. Do not plant into frozen or waterlogged soil to hit a date: a clove kept cool and dry in the shed loses almost nothing.

February and March

The spring route is a proper option, not a consolation. Plant from late February to mid-March using a softneck sold for spring planting, and expect a smaller bulb and an August harvest. Module-raised cloves go out now too, once they carry 5 to 8cm of leaf. Past March the odds fall away sharply.

Planting, step by step

1. Prepare the bed

Pick the sunniest, best-drained ground you have, fork it over and pull the perennial weed roots, then rake it firm and level. On clay, work two or three handfuls of horticultural grit per square metre into the top few centimetres and raise a ridge.

2. Split the bulb and pick the cloves

Break the bulb up on planting day and not before, because a separated clove starts drying at once. Leave each clove in its own skin, plant the plump outer ones and cook the small inner ones, since clove size drives bulb size. Throw out anything soft, hollow or mouldy.

3. Depth, spacing and orientation

Make a hole with a dibber or trowel rather than pushing the clove in, which compacts the soil under the base plate. Set each clove pointed end up, flat base down, tip 2 to 3cm below the surface, and nearer 5cm on light sandy soil where birds and frost heave are the bigger risk. Space true garlic 15cm apart in rows 30cm apart.

4. Firm, label and leave alone

Backfill and firm with your palm rather than your boot, and skip the watering can unless March is dry. Label the row, because garlic stays invisible for weeks and a January fork through it loses the crop.

5. The module route for wet ground

On soil that puddles, fill a deep module tray with peat-free compost mixed with a third grit, one clove per cell, tip just covered. Stand it outside against a wall, not in a greenhouse, so the cloves still get their cold spell. On heavy clay this is what I would do.

6. Keep the birds off

Pigeons and blackbirds pull new cloves out by the shoot in the first few weeks. Peg netting or fleece over the row until the plants are anchored.

What goes wrong, and how to recover

Cloves that rot before spring

The commonest failure, and it is drainage rather than cold: soft brown mush where the clove was, or a gap that never fills. Gap-fill in February with module-raised plants, then fix the cause with grit, a raised ridge or containers.

Supermarket garlic that never performs

Most supermarket garlic comes from warmer countries, from varieties that will not size up in a British summer, and some is treated to stop it sprouting. Leave it if it is already in, but buy certified UK seed garlic for the row you care about.

A single round instead of a bulb of cloves

A smooth undivided bulb the size of a shallot means the cloves never got the cold spell that makes them divide, usually after a spring planting or a mild winter. Sources put that requirement anywhere between four and eight weeks below roughly 10C. The round is good to eat, and replanting it this autumn nearly always gives a segmented bulb.

Rust on the leaves

Orange pustules appear from late spring, worst in mild wet seasons and crowded rows, and there is no cure once it arrives. Feed nothing extra and harvest as soon as the lower leaves die back, which gives smaller bulbs rather than none. Clear the debris off the plot and move the crop next year.

Cloves lying on the surface

A clove lying on top with its shoot bent sideways is bird work, not your mistake: push it back in the same day, right way up, and net the row. Frost heave does the same on light soil, which argues for the deeper end of the range rather than daffodil depth.

Frequently asked questions

Can I plant garlic in September in the UK?

In most of the country, wait. September soil is still warm enough to push soft leaf that the first hard frost knocks back. Elephant garlic and far northern gardens are the exceptions.

Is it too late to plant garlic in February?

No. Late February to mid-March is a recognised UK spring window, best used with a softneck sold for spring planting. Expect a smaller bulb and an August harvest.

Do spring-planted cloves need chilling in the fridge first?

Growers disagree. Some chill cloves for weeks at around 4C to guarantee the cold spell; others hold that a British winter in a shed already does it. After a mild southern winter, the fridge is cheap insurance.

How deep and how far apart should cloves go?

Tip about 2 to 3cm below the surface, pointed end up, nearer 5cm on light sandy soil. Space true garlic 15cm apart in rows 30cm apart, elephant garlic 25 to 30cm each way.