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 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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28 Jul 19, Elizah Thadius (Australia - tropical climate)
Do we have an insecticide/fungicide for bulb onion? Can anyone tell me if there is any manufactured fertilizer for bulb onion?
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29 Jul 19, (Australia - tropical climate)
Look up the internet to see if there is an insecticide/fungicide. The same as my comment for sweet potato. - learn what N P and K do for plants. Then apply that to what you are growing. They don't make different fertilisers for every kind of veggie.
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16 Jul 19, Donna (Australia - temperate climate)
I'm confused I Googled what fertilizer is required for onions and 1 search says onions don't want a lot of nitrogen and another search says onions are nitrogen hungry. ...so which is it?
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17 Jul 19, (Australia - sub-tropical climate)
All plants need some nitrogen. Now if you put a lot of N on the onions, you would have a big green plant above the onion bulb and probably little bulb. N produces leaf and plant structure. Generally if you prepare your soil with compost manures etc and let it all rot in over 6-8 weeks with watering and digging it over, and maybe add a little general fert in the process then you would not have to fert the onions again. A general fert is sufficient to grow most things - look up and learn about crop rotation also.
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24 Jun 19, Cassie (Australia - cool/mountain climate)
And make sure you plant varieties that cope with your particular climate. Many varieties dont cope well with heat and will bolt to seed
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08 Jun 19, Ben Camenzuli (Australia - sub-tropical climate)
What is it that onions do not like as they grow ?? What is they like ? How to prevent onions going to seed ???
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10 Jun 19, (Australia - tropical climate)
Too much N. Water them. Pick them before they seed.
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24 May 19, Yvonne Hermann (Australia - sub-tropical climate)
I bought a large bag of salad(red) onions but due to unfortunate circumstances didn’t get use a lot of them. I now have approx 70 shooting onions. Can I plant these and will they produce new onions? How long from planting to harvesting & is now the right season in Queensland? Thanks in advance Yvonne
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11 Nov 18, Phil (Australia - temperate climate)
I usually grow brown onions which store well, however as we were running out I planted white ones as you can plant them earlier in the season. Now I have heaps of good sized white onions which have just started to run to seed, does anyone have good ideas on how to store them longer than a few weeks?
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13 Nov 18, Mike (Australia - sub-tropical climate)
From what I have read white don't keep as long as brown. Cure them in the sun for a week or so then keep in a cool dry place spread out - probably best to give some away.
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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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