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     T      
        P P            

(Best months for growing Onion in New Zealand - cool/mountain 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 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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08 Dec 19, Susan in Canberra (Australia - temperate climate)
Hi Allan, is it possible that the thinnings were stressed by being pulled out & replanted and this caused them to bolt ahead of the original plantings?
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28 Oct 19, anon (Australia - sub-tropical climate)
My home garden is NS and a men's shed gardens I had were NS. I'm now in a new garden set up that is EW. I have wondered about the difference. My thoughts are with the plantings NS, ALL plants have sun on them all the day whatever hours that is. The sun from the E in the morning and W in the afternoon. With the EW some plants might be shaded by other plants during the day. Different beds could be different soil fertility, hrs of sunlight, watering etc. Generally when soil nutrient and/or water are not sufficient the plant will flower and set seed to be able to reproduce in the future.
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14 Sep 19, petre (Australia - sub-tropical climate)
Hi, Can I buy Onion sets in Australia ?. I live in Canungra Queensland. Thanks, Peter.
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20 Jul 20, Peter Turner (Australia - sub-tropical climate)
Don't buy sets to plant onions. Onions are a biennial crop meaning they flower and set seed in the second year. Onion sets are cold hardened to mimic over-wintering they will think they are in the second year and will go to flower and set seed. This comes at the expense of the bulb getting large.
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16 Sep 19, Anon (Australia - sub-tropical climate)
What do you mean by sets?. I don't grow onions but I would think most people grow from seeds or seedlings.
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27 Aug 19, Jessica (Australia - temperate climate)
Hi, can I still plant onion in September in Melbourne? thank you
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27 Aug 19, Liz (New Zealand - sub-tropical climate)
Check here www.gardenate.com/plant/Onion?zone=2
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10 Aug 19, Sam (South Africa - Summer rainfall climate)
I just planted onions that got spoiled and started to grow but now each bulb has grown into a set of seedlings. Do I pull them out and plant them separately or leave them grow as they are? Kind Regards Sam
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13 Nov 19, anon (South Africa - Summer rainfall climate)
Pull apart.
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13 Jul 20, Elizabeth (South Africa - Summer rainfall climate)
Leave them to grow. Pulling apart will break the roots. A group of onions bulbs will develop and you can harvest them together or one at a time by twisting one gently.
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Hi, I planted out gladalan onions and they are near my snow peas that are flourishing. It says not to plant near peas so (at the risk of sounding silly) does this include snow peas. I am in the shoalhaven area, Nowra

- Kathi Thomas

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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. GardenGrow 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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