Growing Garlic in Containers
Garlic is one of the easiest crops to grow in a pot. It doesn't mind a small space, it's happy on a patio or balcony, and a container can actually suit it better than the open ground if your soil is heavy clay that stays wet through winter. The main things to get right are the depth of the pot, good drainage, and remembering that it still needs a proper winter outside.
Quick answer
Choose a container at least 25 cm deep with drainage holes, and fill it with multi-purpose compost. Plant cloves in autumn, pointed tip up, with about 2.5 cm of compost over the top, spacing them roughly 15 cm apart. Keep the pot outside all winter so the garlic gets the cold it needs, check the compost regularly in spring as pots dry out fast, and lift the bulbs when the leaves turn yellow in early summer.
Choosing a container
Depth matters more than width. The roots grow down well below the bulb, so aim for a container at least 25 cm deep. Good choices include:
deep pots and planters
long troughs and window boxes, if they're deep enough
fabric or potato-style grow bags
Avoid flat tomato grow bags, which are too shallow for garlic to develop a good bulb.
Whatever you use, it must have drainage holes. Garlic sitting in waterlogged compost over winter is likely to rot.
How many cloves per pot?
With cloves spaced about 15 cm apart, and a little room from the edge, a rough guide is:
30 cm round pot: 3 to 4 cloves
40 cm round pot: 6 to 7 cloves
60 cm trough: about 8 cloves, in two staggered rows
It's tempting to squeeze in more, but crowded garlic produces smaller bulbs. Fewer, well-spaced cloves give you a better harvest.
Compost for container garlic
Multi-purpose compost works well on its own. If you have some, mixing in a little grit or perlite helps excess water drain away in wet winters. Avoid using soil dug from the garden, which compacts in pots and drains poorly.
You can read more in best soil for vegetable gardening in the UK
Planting garlic in pots
Plant from mid-autumn to early winter, just as you would in the ground. On planting day, break the bulb into cloves and press each into the compost root-end first, so the pointed tip ends up hidden under a couple of centimetres of compost. Water the pot once after planting, then cover it with netting or fleece for a few weeks to stop birds pulling the cloves out.
For timing, see when to plant garlic in the UK
Keep the pot outside over winter
Garlic needs one to two months of cold weather to form a bulb that splits into cloves. That means the pot should stay outside all winter, not in a warm greenhouse or conservatory, and never indoors. Keep it too cosy and you'll often lift a single, onion-like bulb with no separate cloves.
A few things help it through the winter:
Raise the pot on pot feet or bricks so water drains freely and the base doesn't sit in puddles.
In a very wet winter, move it somewhere slightly sheltered, such as against a wall or under the eaves, where it still gets the cold but less rain.
Don't water unless the compost has dried right out, which is rare in a British winter.
Watering container garlic
Once growth takes off in spring, containers can dry out quickly, especially on sunny, breezy days. Check the compost regularly by pushing a finger in. If it's dry below the surface, water thoroughly.
Carry on watering in dry spells until the foliage starts to turn yellow, then stop. The bulbs are almost finished by then, and wet compost can make them rot.
For watering advice, see how often to water garlic
Position and care
Put the pot in the sunniest spot you have. Garlic won't form good bulbs in shade. A sheltered patio or a south-facing wall is ideal. Snap off any flower stalks that appear in late spring, so the plant's effort goes into fattening the bulb.
Harvesting container garlic
Once the leaves go yellow, pot-grown garlic is ready, which for autumn-planted cloves is usually around May to July. The easiest way to harvest is to tip the whole pot out onto a sheet and pick the bulbs from the compost, which saves damaging them with a fork.
Dry the bulbs somewhere airy for a few weeks before storing, just as you would garden-grown garlic.
For harvesting advice, see when to harvest garlic
For full growing advice, see how to grow garlic in the UK
Common questions
What size pot do I need for garlic?
At least 25 cm deep. Width decides how many cloves you can grow, with a 30 cm round pot holding around 3 or 4.
Can I leave garlic pots outside in winter?
Yes, and it needs to be. Garlic relies on winter cold to form proper cloves. Keep the pot outside, raised on feet so it drains well, and move it somewhere a little more sheltered if the winter is very wet.
Can I grow garlic indoors?
Not successfully. Indoors is too warm for garlic to get the cold spell it needs, so it tends to produce leaves but only small, single bulbs. Grow it outside in a pot instead.
Can I grow garlic in grow bags?
Deep, fabric or potato-style grow bags work well. Standard flat tomato grow bags are too shallow for garlic to form good bulbs.
Growing advice checked against RHS guidance.