Grow, Cook, Eat Know your onions

vegetable of the week Onion

Each week during this season of Grow Cook, Eat (Wednesdays, RTÉ One), the show’s presenters Michael Kelly and Karen O’Donohoe of GIY will share their growing tips and secrets of success with a vegetable you can grow at home. This week, get to know your onions

Why grow onions?

We love onions at GIY because they are one of those vegetables that it’s possible to become self-sufficient in, even if you don’t have a huge amount of space. A decent sized raised bed for example could produce a couple of hundred onions which would be enough for most families for up to a year. They are relatively low maintenance, easy to grow and store well. Above all, there’s nothing better than having onions hanging in your shed and knowing you don’t have to buy those dry, tasteless, imported supermarket onions this year!

Sowing

Generally most GIYers grow from ‘sets’ (basically baby onions) but you can also grow from seed. Sets will mature quickly. Order sets early – the best varieties sell out quickly. Dig in some well rotted manure or compost the previous winter and apply an organic fertiliser (like chicken manure pellets) before sowing. Don’t plant onions in the same place year after year – include in crop rotation.

Plant sets 10cm apart in rows 20cm apart in March/April. Hold off if the weather is very cold – onion sets won’t do well in cold, damp soil. Push the set in to the soil so that the tip is just about visible above the surface. Firm in well. Frost can lift the sets from the soil at night – if this happens, just push them back in the next day. Seed: should be sown in module trays from February and transplant when seedlings are well established.

Growing

Onions hate weed competition so keep your onion bed weed free. Hoe carefully around the bulbs every week or so and hand weed if necessary. Water if weather is dry or mulch (but remove mulch when bulbs start to form), but never overwater. An occasional liquid feed will help.

Harvesting

Onions are ready to harvest when the foliage turns yellow and topples over (approx 20 weeks after sowing). Gently loosen the soil around the onions at this point (or turn the onion very carefully and very slightly in the soil) and leave for another two weeks. Then lift them carefully. Onions can be eaten fresh from soil. For storage, leave to dry on a rack in the sun (or indoors in a greenhouse/polytunnel if the weather is wet) for about 10 days. Then plait them in ropes or hang in nets. If there is a more impressive sight than an onion rope, we’ve yet to see it!

Problems

The most serious disease is onion white rot, which causes leaves to yellow and wilt and bulb gets white mould. There is no remedy but to remove and burn affected plants. You cannot grow onions in that spot for up to 7 years. GIY recommended varieties are Centurion, Red Baron and Sturon.

Tips

l Baked onions – leave the skins on, cut in half and bake for 45 mins – a revelation!

l If your onions ‘bolt’ and produce a flower spike on the stalk, remove immediately or the onions will become bitter.