The onion family is one of the world’s most popular crops, despite making us cry and tainting our breath. As with the bitterness in herbs I mentioned a few weeks ago, the plant’s defensive chemicals, which are designed to deter marauding herbivores, draw humans in.

As they have been doing for millenia. There are Indian texts dating to 3500BC which mention onions, Greek athletes drank onion juice and rubbed onions all over themselves, but it was the ancient Egyptians who took the biscuit. Onion rings symbolised eternal life, so priests were pictured holding bouquets of them, altars were swathed in onions and murals were suitably decorated. Even the mummy of Rameses IV showed signs of having onions placed in his eye sockets.

Gardeners (usually) have different plans for their onions. As they start ripening over the next few weeks, check for signs that they’re ready for harvest.

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Before garlic or onions are ready, some may bolt and sprout a hard flowering stalk. They should be dug up immediately. Premature bolting occurs when plants are stressed and there could be several reasons for this. The onion family needs fertile, well-drained soil and should be spaced well apart: 12-15cm for onions, shallots need 25-30cm, 30cm for garlic, and 20-25cm for leeks. While growing, they need copious amounts of water, either from the heavens or irrigation.

Perhaps the most common cause of bolting is an irregular supply of water, such as when a wet spell follows a prolonged dry one. Stressed by the drought, the plants are triggered into flowering by the welcome rains.

Cutting off the flowering spike won’t help the bulb to keep growing; the only solution is to lift the onion as quickly as possible, cut off and compost the stalk and use the onion immediately. It will not store.

Lift bolted garlic and use the green cloves straight away. You can chop up a garlic stalk and either throw it in a stir-fry or put it in a stew. With limited space and no room for storing, grow a few plants to use during summer and early autumn. We always have garlic to use immediately, even if it’s bolted.

Keep the onion bed free of weeds, especially when you need the sun for ripening the swelling bulbs. Over the next few weeks, roughly three to four months after planting, onions and shallots should be fully grown. Timing for garlic depends on whether they’re autumn or spring planted. You’ll have lifted an autumn one by now, and the later planting should be ready in August or September.

The tips of onion leaves turn yellow when ready to lift and the growing shoot may fall over. If it doesn’t and the bulb looks otherwise ready, don’t bend over the shoot, as was recommended in the past. With garlic, the outer leaves start yellowing to show they’re ready.

After knocking soil off the roots, let all the bulbs dry for two to three weeks, ideally outdoors in the sun. Keep the bulbs off the ground and allow for good air circulation. During a dry spell, I hang the bulbs over the kitchen garden fence, but most summers I have to keep them out of the rain in the woodshed.

After a couple of weeks clean the bulbs. Peel back and remove all the outer skins until you reach a clean, healthy-looking one. Be cruel to be kind: it may seem wasteful to discard part of the onion, but if it’s damaged and has unsightly black spots on it, the bulb simply won’t store.

After cleaning up, put firm, healthy onions aside for storing and use soft and thick-necked specimens fairly quickly. Store garlic, onions and shallots in trays in a cool, frost-free shed, or strung and hung up in the classic style of a French onion seller.