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How to grow onions in your garden

These aromatic alliums are so amazing, you could almost cry!
How to grow onions

White onions are my favourites. I love the pearly, papery cover, the easy-peel function and the sweet, mild taste. But my one attempt at growing them was a failure. My fault, not theirs.

So I’ve decided that this time around, I’ll grow shallots. The French use them all the time, which is recommendation enough, and according to my exhaustive, if reluctant research, they’re also sustainable. They’re a type of mild onion, grown from little bulbs taken from the main plant. Once they’re established, you can keep your supply going indefinitely by saving a few bulblets each year. Bulblets. Lovely word.

Happily, you can start planting these from February, but if I don’t get my act together, any time from then until October is fine.

It’s recommended to soak the bulblets in cool water for about 15 minutes before planting, but I’m not sure why. I usually do half one way and half the other so I can see which is most successful, but by the time they’ve matured, I’ve usually forgotten which is which.

You can grow shallots from seeds or from bulblets. The bulblets give a quicker harvest and are less work. Separate the sections and plant them about 15cm apart, with the pointed end up and just sticking out of the soil. As they grow, mound the soil up around the base of the plants.

When the leaves start to brown off and fall over, about 100 days from planting, don’t berate yourself. They’re ready, not dead. Each bulblet should yield 10 or more shallots. Dig them out gently, clean off the soil, and put them on a wire rack in a shady, dry place for about three weeks to cure. Then pull off the dried tops and store the shallots somewhere cool. Don’t put them anywhere near apples or tomatoes or the ethylene gas these give off will make them sprout.

Shallots look like an onion on the outside and a garlic bulb inside. They have a mild, sweet flavour.

Scallions are not quite so straightforward. People often call young onions harvested before they make bulbs scallions, but the real ones are specialised onions whose bulb at the base is about the same size as the bottom of the leaves. Just to confuse us, they’re also called “bunching” onions.

You can sow scallion seeds in early spring to harvest in summer, then again in late summer to harvest in fall or early winter. Sow in full sun with the seeds about a centimetre apart, in rows around 3cm apart, and thin them out later.

They like well-drained soil, and regular moisture. They’re not especially hungry, so throw some compost in when you plant and they probably won’t need seconds. Mound the soil around them as for shallots and keep them well weeded.

Harvest them when they’re about 15cm tall. Small ones will be milder – the bigger they grow, the stronger the taste.

You could try growing tree onions, otherwise known as walking onions or Egyptian onions. They have a cluster of bulblets where a normal onion would have flowers. The bulblets sprout and grow while still on the original stalk, which bends under the weight of the new growth and takes root a distance away – hence the name “walking onion”. Too clever.

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