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

01 Jul 14, Barb (Australia - temperate climate)
Hi Jo, Sounds like black aphids. I plant a heap of flowers in the vegie garden to encourage predatory insects that eat aphids. But if you have so many aphids, it might be that the plants are unhealthy, which means the soil might not be good. I'd be inclined to add some good compost to the soil (well matured for onions) and also foliar feed the onions with a liquid seaweed such as seasol to help make the onion plants more resilient. Also good to interplant them between lettuce as this seems to help hide the onions from the bugs while they're young and vulnerable.
29 May 14, (Australia - temperate climate)
I have just bought 1 kg of onion seed and may not use all of it this year, will the seeds still be good to use in a year's time? Thanks
20 May 14, Maurice (Australia - sub-tropical climate)
There are a few perennial varieties of onion around so you do not need to mess around with saving seed and planting seedlings each year. They are hard to find but easy to grow, they seem to grow well even here in the tropics. I am very happy with mine, I got them from living-mudflower.blogspot.com.au/2013/05/perennial-annual-vegetables-for-sale.html
03 May 14, Robin schuboxey (Canada - Zone 2a Sub-Arctic climate)
I reccommend you grow your Australian onions in seed trays before you plant them in the garden. It works here in Canada at minus zero so it surely must work in your warm Australian soil
05 Apr 14, Dave (Australia - sub-tropical climate)
My onions are growing ok but they are all lying down instead of standing up. Is there something I should be doing to make them stand up?
22 Feb 14, Ali (Australia - temperate climate)
I am still drying out on onions I have taken it the top the the onion(where all the seeds are) but they are still green. What do I do? When do I plant them? Would they turn out okay!!?
10 Feb 14, kathleen harris (Australia - temperate climate)
Can you recommend a variety of onion that I can grow for pickling. The pickling onions in the shops are too big and not nearly crisp enough.
07 May 14, Ted (Australia - temperate climate)
Kathleen we plant out cream gold for pickling have done it for years. Plant them close together rather thickly and harvest in summer. They can sit around for ages if needed before you pickle them. Very crisp.
06 Nov 13, doug Dewar (Australia - arid climate)
i have planted onions and spring onions over the top of pea mulch and a lot of seeds have germinated, i have been pulling them out as they come up and finally they have all gone.Should i use sulphate of potash to balance out the high level of nitrogen in the soil as i do not want to lose them because they take so long to grow,hoping you can help me,thanks doug dewar.
07 May 14, Travis Edwards (Australia - temperate climate)
If anything you will find that the decaying pea straw will be sucking nitrogen out of the soil while it is decaying once it has composted down well it will be nitrogen rich however. lime, and gypsum, would be a good additive as the decay process tends to be acid and onions prefer a slightly alkaline soil. (lime and gypsum will help neutralise the acidity.)
Showing 131 - 140 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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