The humble onion is one of our most important vegetables. It’s a staple ingredient in many different recipes from soups and casseroles to pasta sauces and quiche fillings. Onions are packed full of nutritional benefits too. They are a source of vitamins A, B6, C and E, and also contain minerals such as sodium, potassium and iron.
Having a ready supply of onions at home is really useful – you only need to add a couple of extra ingredients to whip up a quick meal. And if you use a lot of onions, you might want to have a go at growing your own. It’s surprisingly easy and with your own supply, you’ll always have an onion or two when you need them.
Growing Onions
Onions can be grown in a home garden either from seeds or from baby onions called ‘sets’. For best results, onions should be planted in open ground however, if you don’t have a garden, you may be able to grow onions successfully in deep containers on a patio or in a backyard.
Onions prefer a sunny position in a sheltered area and need well-drained soil. However don’t plant in freshly manured soil as this can lead to rotting.
If using onion sets, these should be planted from mid-March to mid-April. Plant the sets 10cm apart, in rows which are 30cm apart. Keep just the tip showing above the soil level and gently firm the soil around the tips.
If using onion seed, sow the seeds from late-February to early-April, 13mm deep, in rows 20cm apart. When seedlings appear, thin them to 5cm apart and then later thin again to 10cm apart.
You can use mulch to help conserve moisture in the soil and help prevent weeds. Water your onions in dry weather and feed using a general liquid fertiliser.
Harvesting
It’s easy to tell when your onions are ready to harvest as the green tops will lose their colour and the tops will begin to bend over. Once the tops have fallen, you should leave the onions for a further 10-14 days to fuller mature.
It’s best to harvest your onions on a dry day; this way they will retain less moisture making them easier to store for longer. Many of the onions will appear at the soil’s surface so will be easy to pick by hand, alternatively use a fork or trowel to reach them.
Storing
The great thing about onions is that they can be stored for a long time so if you have a bumper crop, you don’t have to worry about eating them all at once. However, before storing your onion harvest, you need to cure the onions. This dries out the outer skins to protect the onion from rot and mould.
To cure your onions, simply lay them in a single layer in a dry, warm environment for two to four weeks. Once the neck of the onion has withered and tightened around the bulb, the skin has become papery, and the roots feel dry; the onion is ready to store. You can trim the roots before storing and then simply keep your onions in a cool, dark place until you need them.
For more information about growing onions, visit: www.rhs.org.uk/advice/grow-your-own
