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        
        P              

(Best months for growing Onion in Australia - sub-tropical 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

Your comments and tips

02 Jan 17, Bob (Australia - temperate climate)
I'm in Sydney NSW, and I think I'm in the temperate zone. is that correct Cheers
03 Jan 17, John Mauger (Australia - temperate climate)
Sydney would be temperate but you can grow a lot of subtropical things there as well. A lot of Sydney does not get frosts.
10 Dec 16, John (Australia - temperate climate)
I would like to grow some red onions I can not find seeds but I brought some bulbs from the local green grocer now do I plant the bulb in the garden or do I keep them in the cupboard or fridge till they spout I live in Tasmania
10 Dec 16, John (Australia - temperate climate)
Onions are biennial; that is, they grow and die down the first year then sprout again and flower in the second year. I would plant the bulbs as they will grow and flower this season giving you an abundance of seed. There is a seed company called The Lost Seed in Tasmania and there was another called Phoenix Seeds, if you googled them I am fairly sure one of them would have red onion seed. Trust this helps.
29 Nov 16, linda davies (Australia - temperate climate)
my onions are very big and some are going to seed. Should I leave them to dye back or pull them and leave on racks to dry.
29 Nov 16, John (Australia - temperate climate)
Normally onions go to seed in their second year. You could bend the stems at bulb level so they are basically crushed and lying flat. this will trigger ripening snd when the the top dies off you will be right to harvest and store them. Yhis has worked for me and I've heard it talked about by other gardeners.
15 Nov 16, Bob (Australia - temperate climate)
I planted white onions seedlings (variety unknown) in mid-June with the usual expectation that they would be ready for harvest in early December; when the tops usually start to dry out. This year about 50% of the plants have started to produce flower buds in early November. I suspect that if I allow them to flower; the quality and storage-life of the onions will be reduced. Should I harvest them before the first flowers blossom? Regards Bob.
18 Nov 16, John (Australia - temperate climate)
Onions are biennial, that is they grow and die down in he first year then regrow and flower/seed in the second year. If seedlings of biennials are stressed in the punnets before they are planted or if the variety is not suitable for planting at the time of the year the plants may be triggered to flower and set seed. If you leave them they will increase like daffodil bulbs.
25 Oct 16, Trish (Australia - temperate climate)
Hi - I want to use the seed from my onions to plant for the next round. How should I do this?
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! ;)
Showing 91 - 100 of 192 comments

Why are my brown onions growing up as spring onions?? I have even rung the company of the seeds and they sent me two new packets of seeds out. I planted some of them and they are still coming up as spring onions. Please help

- Sandra Millhouse

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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. Gardenate 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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