Why garlic thrives in pots and raised beds

Garlic is one of the most forgiving crops a UK grower can attempt, but it has two firm requirements: free-draining soil and a good cold spell. Raised beds and containers meet both beautifully. A raised bed lifts the root zone above the winter water table, which is exactly what garlic needs through our damp autumns and springs, while a decent-sized pot gives you complete control over the compost mix and lets you move plants under cover if a wet spell drags on.

Containers also solve the white rot problem. If your allotment soil has a history of onion white rot, growing garlic in fresh compost in pots is often the only way to get a crop at all. Add the fact that garlic takes up very little space for eight or nine months and it becomes an easy crop to slot in between summer salads and next year's beans.

Pick the right cloves for British conditions

Garlic divides into two broad types. Hardneck varieties, such as 'Music' or 'Purple Wight', produce a stiff central stalk and a flower spike called a scape. They are hardy, cope well with cold winters and tend to have the strongest flavour, but they store for less time. Softneck varieties, including 'Solent Wight' and most supermarket-style bulbs, have softer stems that can be plaited and keep far longer.

Autumn planting, from October to early December, suits almost every part of the UK and gives the biggest bulbs. Spring planting in January or February is possible, especially with softnecks, but expect smaller results.

A few rules before you buy:

• Buy certified seed garlic from a specialist grower rather than planting supermarket bulbs, which are often treated to stop them sprouting and may carry disease.
• Elephant garlic is a different species entirely — it is milder, milder-storing and takes up a lot of room, so treat it separately.
• Choose varieties suited to your climate: hardnecks for cold, wet northern gardens, softnecks for milder southern plots.

Planting cloves the right way up

Split the bulb into individual cloves just before planting, keeping the papery skin intact. Plant each clove pointed end up, flat base down, about 3cm deep in pots and 5cm deep in a raised bed. Getting the orientation right matters: an upside-down clove will still grow, but it wastes energy twisting around and produces a poorer bulb.

Space cloves 15cm apart in beds, with 20–25cm between rows. In containers, use a pot at least 20cm deep and 25cm across, and plant no more than three cloves per pot of that size — garlic resents crowding. A 30cm pot will take four comfortably.

For compost, mix a good multipurpose or John Innes No. 3 with roughly a quarter by volume of horticultural grit or coarse sand. Add a couple of handfuls of garden compost or wormcastings for fertility, but avoid fresh manure, which encourages lush, soft growth that rots in winter. In raised beds, fork in grit and compost to a spade's depth and rake the surface level before planting.

Tuck the cloves in, firm the compost gently and water once. Then leave them alone.

Watering, feeding and winter care

This is where most beginners go wrong. Water sparingly until shoots appear, and keep them on the dry side right through winter. Garlic is a Mediterranean plant at heart and soggy compost is its main enemy. In a raised bed, only water during genuinely dry spells — usually you will not need to between November and March. In pots, water when the top 3cm of compost feels dry, which may be once a fortnight in winter.

Once growth is strong in spring, water more freely, aiming for consistently moist but never waterlogged compost. From April onwards, feed every fortnight with a high-potassium liquid feed — tomato feed or diluted comfrey tea works well. Nitrogen-heavy feeds give you leafy tops and small bulbs, so hold back on general-purpose fertiliser.

Keep the bed or pot weed-free. Garlic has shallow roots and does not compete well. A light mulch of compost in early spring helps suppress weeds and conserve moisture.

Pests, diseases and common problems

• Rust: orange pustules on the leaves, usually after a wet spell. Remove badly affected leaves, improve airflow and avoid overhead watering. Affected plants still usually crop.
• Birds: pigeons and crows sometimes tug newly planted cloves out of the ground. Netting or a few short twigs laid over the bed solves it.
• White rot: yellowing leaves and a fuzzy white mould at the base. There is no cure — bin the plants and never replant garlic or onions in that compost or soil.
• Leek moth and allium leaf miner: look for tunnelled leaves in spring. Remove affected foliage and keep plants growing strongly.
• Small bulbs: almost always caused by overcrowding, too much shade or planting too late.

Harvesting, drying and storing your crop

Stop watering about three weeks before you expect to lift. Hardnecks are ready from late June, softnecks from July into August. The signal is simple: the leaves begin to yellow and topple over. Lift when roughly half the foliage has died back — leave it any longer and the bulbs split and will not store.

Ease the bulbs out with a fork or tip the pot out gently. Do not pull by the stem, as it can tear away from the bulb. Brush off loose soil but do not wash them. Cure the bulbs in a warm, airy, dry spot — a greenhouse shelf, a shed with the door open, or a sunny windowsill — for two to three weeks until the skins rustle and the necks are dry.

Store hardnecks in a cool, dry, dark place and use them by midwinter. Plait or tie softnecks and they will keep until spring. Keep a few of your best bulbs back and you will never need to buy seed garlic again.