Growing Onion

Allium cepa : Amaryllidaceae / the onion family

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

(Best months for growing Onion in Australia - tropical regions)

  • S = Plant undercover in seed trays
  • T = Plant out (transplant) seedlings
  • 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

Your comments and tips

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27 Oct 16, Tempest (Australia - temperate climate)
Leave your best/biggest onion(s) to go to seed. It may take a while, but it's worth it to have all the extra seed. My friend did this but wasn't able to harvest the seed when it was ready - she now has lots of onions popping up around the original onion. Best excuse for less effort! ;)
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10 Jul 16, Cassie (Australia - cool/mountain climate)
So why did my onions grow well then split and sprout? They have no intention of having their tops die back. Previously I've had them go to seed and clearly avoid the whole 'tops dying back' thing too. I sow seed in late winter and plant out the seedlings in early spring. What am I doing wrong?
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18 Jun 16, Christine (Australia - tropical climate)
I have onions shooting in the vegie bin. My son said when I plant them I have to put the new growth above the soil, but I though this was the root. Which way do I plant them please?
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01 Jul 16, Barb (Australia - temperate climate)
Your son is right - the green shoots are the stems/leaves starting to grow. So plant these uppermost. I find the ones that I grow from shooting onions may not bulb up properly. but they make great spring onions, and if left will divide so you'll have a little patch of spring onions.
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01 Jun 16, Annie (Australia - cool/mountain climate)
In regards to soil temp for onions. You suggest 8-30 degree temps are best but my app is saying plant in garden now, (Natone, Tas) We are currently getting 2-15 degrees on average and dropping with morning frosts. Will onions survive or do they need to go into the hothouse?
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26 Jun 16, stephen kettle (Australia - cool/mountain climate)
Hi Annie, I'm in Latrobe, and I've always planted onions out on , or around the shortest day
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29 Apr 16, Daniel (Australia - temperate climate)
I'm trying an idea of planning the base of spring onions I buy at the green grocers after eating the top portion. Has any else tried this?
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01 May 16, Jordan (Australia - sub-tropical climate)
Yep, works a treat. Put the bottoms in water to let them grow roots and transplant.
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27 Apr 16, Noel Oliver (Australia - temperate climate)
What month to plant red onion seed and brown onion seed
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30 Apr 16, Paul (Australia - arid climate)
Onions can be grown all year round and with regularly planting seed every month you will have a continuous crop. Always let the most vigourous go to seed so you have a constant supply as onion seed does not remain viable for too many years, 3 tops if you want good germination rates.
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