Growing Onion

Allium cepa : Amaryllidaceae / the onion family

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

(Best months for growing Onion in USA - Zone 5a regions)

  • S = Plant undercover in seed trays
  • 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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01 Jun 11, arthur (Australia - temperate climate)
I find the best way to store onions pull them, leave them exposed on top of the ground for two days or until the are brown then platt them like they do in spain. Hang if possible from roof of a shed or such like. ( arthur the mad gardner).
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08 Apr 11, allan (Australia - temperate climate)
onion seedling have died from the tip down like thay have burnt off . planted two punnets 2/3 lost . Thought it was spraydrift howerver replanted & has started to die back again could it be sheep manure not rotted enough . Think sheep is high in potash would do it
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04 Feb 11, stuart (Australia - temperate climate)
plant onions on the winter solstice
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01 Mar 11, Brianna (Australia - temperate climate)
I like to plant my onion seedling out on the winter solstice, as they are less inclined to go to seed and more likely to create nice big onions. If they still try and flower I just cut the flower off and bend the whole top over and generally they still create nice bulbs. To do this I start the seeds off in a tray 4-6 weeks before the winter solstice.
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07 Nov 10, Gema gonzalez (Australia - sub-tropical climate)
what do they need, phosforos, iron...potasium? please let me know
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01 Jan 11, Daniel (Australia - temperate climate)
Onions need a fairly mellow compost. The best conditions to grow onions in would be to have a very rich composted bed which you grow something like tomatoes or zucchinis in (heavy feeders) and once those summer crop are finished plant onions in to that same soil. That will give you the best onion results. Onions also require a cold period to form the bulb
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29 Oct 18, Sue Spriggs (Australia - temperate climate)
My onions always go to seed. What am I doing wrong?
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27 Oct 10, sharon (Australia - temperate climate)
I live in the Adelaide hills and i have my onions in since May this year they are starting to get flowers on the top and some bulbs are under the ground as i hilled them a couple of time not knowing thay should be on top of the ground. should i take some dirt away as they have very thick stems and bend the tops over to stop them from going to seed or just pull them up.???
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12 Aug 10, Mohan (Australia - temperate climate)
I was in India last month and came across white onions. It is said white onions have medicinal properties. Are the seeds available in Sydney.
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10 Aug 10, (Australia - sub-tropical climate)
hello I am a bit confused about the soil.CanI use blood and bone before planting the seedlingsas Iam getting conflicting reports what has worked for you to get the best results
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Showing 341 - 350 of 379 comments
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I took a look at the I'iotoi onion on google, the photo of them is the closest /the same to what I grow. I have always called them shallots and so did my mother. I/we have been growing them for nearly 60 years. Keep bulbs from one year to the next to replant. The only problem is I live in Australia, near Bundaberg Qld. A lot of people call different things shallots. If you are unable to obtain any in NZ you could ring your agric department and see if I could send some to you. Ring up some of the seed selling companies in NZ to see if they have them.

- Mike

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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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