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

04 Feb 11, stuart (Australia - temperate climate)
plant onions on the winter solstice
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.
07 Nov 10, Gema gonzalez (Australia - sub-tropical climate)
what do they need, phosforos, iron...potasium? please let me know
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
29 Oct 18, Sue Spriggs (Australia - temperate climate)
My onions always go to seed. What am I doing wrong?
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.???
12 Jul 10, Sue Summers (Australia - temperate climate)
I live in the Bass Strait Islands north of Tassie, I want to know the best onions to plant for making pickled onions (brown variety). Also how do I know when to harvest them?
17 Apr 10, Chris (Australia - cool/mountain climate)
Fritz - a cool place for storing onions is in a bottom cupboard or similar. Anywhere that doesn't get hot. They tend to go mouldy in a fridge
16 Jan 10, Fritz (Australia - temperate climate)
My Brown Onions seem to be ready to harvest.How do I store them? What is a cool Place ? Do i keep them in the Fridge or just in the Kitchen cubboard? In Paper Bags/
25 Oct 09, mick (Australia - temperate climate)
hi i use to grow hunter river white onions and just cant find where i can buy seed anymore .I live in the wollindilly distric ?
Showing 161 - 170 of 192 comments

I have the same issue as Kate. My onions are looking great, getting bulbs. I don't want to wait too late in case they start bolting. But I don't know when to harvest them. Or to bend the stems over or just pull them, which is what I've done before. They still have thick stems.

- Annie

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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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