When planning to grow onions there are a few things you need to consider;

1. Whether you want to grow from seeds or sets.
2. How you plan to use the onions you grow.
3. How much space you have available.

The answers to these questions will send you in circles if you are not careful. Space is your ultimate driver, if you have plenty then you can grow enough onions to feed your family all year round. If limited consider what you plan to use your onions for. If you eat a lot of salads through the summer you might want to grow spring or salad onions and therefore seeds are a better starting point. If you want the joy of growing for cooking and don’t want to fuss with seeds then sets are your best option.

How many Onions do you need?

As with any plant the better you look after it the better results you will see. In the case of onions if you plant 1 onion set your will harvest 1 onion. If you look after that onion, feed the soil it is to grow in and water as needed it will grow large, if you leave it to suffer with little food and water it will grow small. Therefore consider how much space you have allocated to your crop and buy accordingly. Sets should be planted approx 10 cm apart in rows 20 – 30 cm apart, seedlings and thinning out of seedlings to about the same distance. This allows enough space for good sized onions to develop. Spring onions and onions for pickling can be sewn closer together.

Soil preparation

Onions benefit from good soil, prefer a sunny spot and like a firmer ground to grow in. It is best to dig in the compost or manure and allow the ground to settle well before planting time.

Sewing the seeds

Sewing time, for seeds, depends upon the variety you choose to grow . Seedlings grown for transplanting will need to be hardened off if not grown under glass or will suffer frost damage. Seedlings grown over winter in situ should be fine unless we have a particularly hard winter.

Seeds should be sewn either thinly in pots or in a drill approx 1cm deep, lightly covered with soil and watered in. Rows should be approx 20 – 30cms apart.

• If transplanting - plant the seedlings in a hole approx 2cm deep,  10 cm apart in rows 20 - 30cm apart.
• If thinning – thin the seedlings when approx 5 cm high until you have onions  10 cm apart in their rows. These thinnings can be eaten as salad onions or passed on to other growers.
• Sets should be planted approx 10 cm apart in rows 20 – 30 cm apart with their tips just above soil level. After 2 weeks check and replant any that have surfaced, the birds may have been pulling them out or their new roots may have pushed them up, either way they’ll need a push back down.

Plant care

As the plants mature you will start to see the onion bulb swell. It is not unusual for up to half the onion to be above ground level. Plenty of water will help you to produce a better crop of larger onions. If the weather is dry, especially as the bulb is forming, water them regularly. If they don’t get enough water your plants may start to bolt, produce flowers and go to seed. If this happens the onion will produce a thick flower stem, all the goodness in the onion bulb will be used to produce the flower head and you will have no onion. There is nothing you can do to reverse this process so if they start to go either pull the onion and use it early in salads etc or leave it and enjoy the flower, remember to collect the seed for next year.

Growing onions in containers

Container growing is ideal for salad or spring onions as they need less space than main crop onions and can be succession grown . If you keep 2 or 3 containers of onions on the go as you use up 1 batch replace the compost and sew some more. Keep the containers near the kitchen and your salad onions will always be handy when you need them. Make sure you keep them well watered.

Happy growing!