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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17 Jan 18, Joe Branco (Australia - temperate climate)
Why are brown and white onions sown at different times
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04 Dec 17, andrew heaps (New Zealand - temperate climate)
hi,my onions have thick stalks just above the onions them selves.is that normal?and if not what is the remedy?
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29 Oct 18, hamish (New Zealand - cool/mountain climate)
more than likely planted a little too deeply at start warm regards hamish
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27 Nov 17, John (Australia - temperate climate)
Hello and thanks for your time I would like to grow red onions i live in the wrstarn suburbs of Adelaide when do I plant seed thank you .
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01 Dec 17, Mike (Australia - temperate climate)
Read what it says above - it tells you.
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14 Nov 17, rob (Australia - temperate climate)
onions are going to seed . Should I pick now or wait till they brown
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20 Nov 17, Mike (Australia - cool/mountain climate)
In future pick before they seed or when you first see them starting to seed.
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15 Nov 17, Mike (Australia - sub-tropical climate)
Pick them and then leave in the sun for a few days to brown off.
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24 Oct 17, Danie (South Africa - Summer rainfall climate)
Why shouldn't onions be planted close to beans and peas?
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17 Oct 17, Danie (South Africa - Summer rainfall climate)
Do I have to roll the leaves of the plants to enhance bulb forming at this time before they are harvested to prevent new growth?
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Showing 181 - 190 of 368 comments
See comments for all plants

Onions can be raised in seed trays or punnets and transplanted when about 10-15cm tall. They should be planted with just the roots covered. If sown direct, the emerging plants may need thinning. I have been successful with both methods for brown and red onions and with spring onions from seedlings.

- Liz

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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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