Growing Onion

Allium cepa : Amaryllidaceae / the onion family

Jan F M A M J J A S O N Dec
  S         S          
      T T T     T      
        P P            

(Best months for growing Onion in New Zealand - cool/mountain regions)

  • S = Plant undercover in seed trays
  • T = Plant out (transplant) seedlings
  • P = Sow seed
  • Easy to grow. Grow in seed trays, and plant out in 4-6 weeks. Sow seed at a depth approximately three times the diameter of the seed. Best planted at soil temperatures between 8°C and 30°C. (Show °F/in)
  • Space plants: 5 - 10 cm apart
  • Harvest in 25-34 weeks. Allow onions to dry before storing.
  • Compatible with (can grow beside): Lemon Balm, Borage, Carrots, Beets, Silverbeet, Lettuce, Amaranth
  • Avoid growing close to: Peas, Beans
  • Red onion
  • Young brown onion

Onions come in a range of colours and shapes and sizes. Brown - strong flavour and pungent. Usually good keepers for storage. White - milder but still flavoursome. Keep fairly well. Red - Mild, suitable to use raw in salads and sandwiches. The seedlings should be allowed to gain a bit of strength before planting out - usually 4 to 6 weeks will be enough. When they are big enough to handle, you can plant out. They start off looking like blades of grass.

They don't have to be in a greenhouse (though that would be ideal), any sheltered spot will do. The idea is to guard against rapid changes of temperature, especially at night.

Onions can be bought as young plants (sets or seedlings) from garden shops/nurseries to plant straight into garden beds. Choose your variety according to your climate and the time of year as some onions will grow better in the cooler months .

Onion bulbs should sit on the surface of the soil. Do not cover. They will take six to eight months to mature. Onions are ready when the tops start to dry and fall over. Pull them and leave to dry for a few days. Store in a cool, dry airy place. Use a net bag or make a string by weaving the tops together.

Culinary hints - cooking and eating Onion

Brown onions roasted whole with other vegetables are delicious.
Red onions add colour to salads or stir-fry.

Your comments and tips

04 Mar 24, Mary (USA - Zone 8a climate)
Do onion sets do well in a container?
07 Feb 24, Brenda (USA - Zone 5a climate)
What do you mean when you say plant out
07 Feb 24, (USA - Zone 5a climate)
Hi, it means to take the seedlings you've grown from seed, and plant them in the ground or bigger pots.
08 Feb 24, (USA - Zone 5a climate)
Thanks
26 Dec 23, alfred rockhold (USA - Zone 6a climate)
i live in wv
09 Dec 23, Gill (New Zealand - temperate climate)
How much watering do onions like. On tank water so hoping not heavy drinkers
14 Dec 23, (New Zealand - sub-tropical climate)
Just give a watering 2-3 times a week depending on how hot it is.
29 Nov 23, Themba Peter (South Africa - Summer rainfall climate)
I have onions that need transplanting is it the right time, will appreciate the advice.
30 Nov 23, (South Africa - Summer rainfall climate)
You could try but it does say Feb - April.
08 Sep 23, enie (South Africa - Summer rainfall climate)
is there onion variety that you can grow around November in south africa
Showing 1 - 10 of 357 comments

when is the best time to put in red onion in christchurch

- robert samuel walker

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This planting guide is a general reference intended for home gardeners. We recommend that you take into account your local conditions in making planting decisions. GardenGrow is not a farming or commercial advisory service. For specific advice, please contact your local plant suppliers, gardening groups, or agricultural department. The information on this site is presented in good faith, but we take no responsibility as to the accuracy of the information provided.
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