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 46°F and 86°F. (Show °C/cm)
  • Space plants: 2 - 4 inches 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

Your comments and tips

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10 Jul 21, (Australia - sub-tropical climate)
All the onion family are pretty similar to grow. Plant them similar time as spring onions and leeks. If you want more info google
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08 Aug 21, anne onn (Australia - temperate climate)
telling people to google something on a plant website is just lazy. @Jacqueline, you can safely plant the red onions as if they were spring onions, just allow for more space between the plants Note: Gardenate does not advise google - we assume that is how the questioner found our site)
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07 May 21, Pablo checkman (South Africa - Dry summer sub-tropical climate)
How many month it takes Africans best onion
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10 May 21, (South Africa - Semi-arid climate)
Read the notes here, www.gardenate.com/plant/Onion?zone=22
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02 May 21, Michele (New Zealand - cool/mountain climate)
I seem to have gotten white rot/fungus tha affects most onion varieties except spring onions- they will get it but very late on...does anyone know of a vigorous type of ordinary brown or red onion that might stave it off until I can harvest? Thanks.
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10 May 21, Tony (New Zealand - temperate climate)
try spraying regularly with copper, also good for rust.
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06 May 21, Anonymous (New Zealand - temperate climate)
Ring your local agricultural or agric company department about the fungus.
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06 Apr 21, Duke Rick (USA - Zone 8b climate)
What is the best time to plant Maui onion seeds in my zone?
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05 Jan 22, don (USA - Zone 10b climate)
when you are on this page - just above the title
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02 Apr 21, Debbie h. (USA - Zone 9b climate)
Can you plant onions that already have a green stem coming from it? Like ones in fridge if not used fast enough .
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Showing 91 - 100 of 383 comments
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Onions are generally fairly easy to germinate. They need to be planted about 3 times their diameter with soil. A good way to do this is to sprinkle the seed over a small area that has been broken up and is very fine then cover with some more fine soil. Keep the soil damp but not wet. When the seedlings emerge they will be very fine like a needle. keep them damp but not wet as they may get fungus problems. A spot that gets some sunshine and a bit of airflow is good. They will take about 4-6 weeks before they are ready to transplant into rows in the garden. They will take about 6 months to be ready to harvest and store (when the tops flop over and start to dry). I hope this helps. Don't hesitate to ask questions, we are here to help.

- John

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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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