Growing Onion

Allium cepa : Amaryllidaceae / the onion family

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

(Best months for growing Onion in USA - Zone 9a regions)

  • 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 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

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22 May 20, Anonymous (South Africa - Summer rainfall climate)
Gardenate suggests you plant Feb to April. Try planting it in August and it probably won't even germinate. Most plants have a defined time of the year to grow in a particular climate zone.
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12 May 20, Anon (South Africa - Semi-arid climate)
Check the top of the page .
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08 Apr 20, Harpreet Kaur (New Zealand - cool/mountain climate)
If you sow seeds of red onion indoor in April and wait till it can be transplanted outside..say in June.. Can it stay in the ground in cold winters harmlessly..n mature in summers to come around Christmas? Or will it die in cold weather buried in soil ?
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09 Apr 20, anonymous (New Zealand - cool/mountain climate)
Go to cool/mountain NZ look up onion and look at the monthly calendar at the top of the page - read what S P &T mean and then apply that to your question.
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01 Apr 20, paul ryan (Australia - temperate climate)
What do you mean by saying onion bulbs should sit on the soil and not be covered.
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03 Apr 20, Anon (Australia - sub-tropical climate)
When an onion grows the bulb part sits on top of the soil, only the roots are in the soil. DO NOT hill the soil up over the bulb. Check on the internet and see.
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01 Apr 20, Kaz (USA - Zone 11b climate)
Aloha What onions & tomatoes grow well in zone 11 Hawaii Ohau north shore
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25 Nov 19, William Rowe (USA - Zone 9b climate)
What variety of onion do you suggest for my region. 9b Ocala,Fl
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26 Oct 19, Allan Kevin Marshall (Australia - cool/mountain climate)
I sowed my Hunter River Brown seeds on the 1st of April in rows East & West I thinned them out & the thinnings I planted in a bed facing North & South .The thinnings are bolting to seed,& the ones planted in the East West are doing well. I live in Geelong Victoria,What could be the fault here with the planting North & South
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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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Showing 141 - 150 of 384 comments
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Absolutely! We do all the time! We always cut the onions we buy horizontally in half when cooking and carefully peel down to the middle chunks where you can see how many "dots" are gonna be onions next year. We have a big patch of sandy loose soil that has a lot of chicken manure and/or compost here or there that we plant all of them in. We plant them an inch or so under the soil (totally covered up is best but not too deep) and we do not break them apart first. They grow into BIG beautiful onions in a year or so if you give 'em a drink of water when its dry for weeks. AND they make seeds too! Good seeds if you let them dry all the way out! We love getting free food from cooking scraps... with a bit of pre-planning on slicing the onions right to begin with... Try replanting carrot tops if you want fresh seeds... the top 2" of a regular carrot grows into fluffy foliage and sends up nice fresh seed heads in late summer. Freebies are fun!

- Melinda Schwab

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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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