How do I dry and cure onions and garlic so they keep?

The neck is the whole story. An onion or a garlic bulb keeps because the neck has dried and sealed, closing the only route into the bulb. A bulb with a soft green neck is an open wound, and it will rot in store however carefully it is kept. Curing is simply the process of drying that neck properly.

Step by step

1. Stop watering as the foliage starts to yellow.Late water keeps the neck soft and delays the whole process. Once the tops start to go over, let the ground dry.
2. Lift when the tops flop naturally.For onions, when most of the row has bent over at the neck and the leaves are yellowing. For garlic, when about a third to a half of the leaves have yellowed. Do not bend the tops over by hand — it damages the neck and shortens storage.
3. Ease them out with a fork rather than pulling.Pulling by the leaves bruises the neck. Lever gently from below, lift the whole bulb with the roots attached, and knock off loose soil with your hand.
4. Dry in a single layer with air all round.A rack, a mesh table, a pallet, wire netting stretched over a frame, or slatted trays. Air needs to reach underneath as well as over the top. Do not pile them up.
5. Choose warmth and airflow, out of rain.In a British late summer, a greenhouse bench with the vents open, an open-sided shed, a car port or a porch all work. Full scorching sun splits the skins; a sealed shed traps moisture and rots them.
6. Give it two to three weeks and test the neck.It should be thin, dry and papery, and rustle between finger and thumb. If it is still thick or feels cool and damp, it is not cured. Keep going.
7. Sort out the ones that will not keep.Any bulb with a thick soft neck, any that has bolted and has a hard stem through the middle, any with a soft base or visible mould, and any with damage — those go in the kitchen now. Only sound cured bulbs go into store.
8. Trim and store.Cut the roots off close and the tops to about 3–5cm, or leave the tops on to plait softneck garlic and onions. Store in nets, open trays or plaits, somewhere cool, dark, dry and airy.
9. Check the store monthly.Feel for softness and look for green sprouting or mould. Remove anything going over before it affects its neighbours.

Tips

• Curing in a greenhouse works well in the UK because the warmth is reliable and the rain is excluded — just leave the door and vents open day and night.
• If a wet spell arrives while the crop is drying outside, bring it in. Rain on partly cured bulbs undoes the work and starts rot.
• Shallots cure exactly like onions and generally store even better.
• Garlic destined for replanting should be cured just as carefully, and the biggest bulbs kept back for seed rather than eaten.
• Hardneck garlic keeps for a few months; softneck varieties can go through to spring. Eat the hardnecks first.

Common mistakes

• Bending the tops over to speed things up — It damages the neck tissue and creates a wound rather than a seal. Let the plant fold over on its own.
• Curing under polythene or in a closed shed — Moisture cannot escape. The classic result is neck rot — a soft, grey, collapsing shoulder that appears weeks into storage.
• Storing bulbs with damp soil still on them — Trapped soil holds moisture against the base plate and starts rot. Let the soil dry and knock it off before storing.
• Washing the bulbs — Water is exactly what curing removes. Never wash onions or garlic before storage.

Keeping on top of it

• Check stored bulbs for softness, sprouting and mould (monthly)
• Turn plaits or nets so airflow reaches all sides (monthly)

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