Growing Onion

Allium cepa : Amaryllidaceae / the onion family

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

(Best months for growing Onion in South Africa - Semi-arid 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 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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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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01 Aug 19, Mwenya Selebi (South Africa - Humid sub-tropical climate)
Where in South Africa Gauteng can l buy red onion seedlings. l have a two hector onion field. l did direct planting of the onion and only one hector has come out well. l need seedlings that are ready for transplanting to supplement, csn you help me please. Where can l.buy seedlings in Gauteng.
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18 Apr 19, SHIREEN WALTERS (South Africa - Summer rainfall climate)
Can I plant spring onions and coriander now (middle April) ?
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29 Apr 20, Allimuthu Perumal 0329443959 (South Africa - Summer rainfall climate)
Yes you can but try a tomato box size for coriander
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26 Nov 18, raymond (South Africa - Humid sub-tropical climate)
May I know, When to plant onions in an area of Bioresource Group no 1 (Moist Coast forest?) .My mom wants to plant it on a correct time. I ll be a great pleasure to know. Thanks. Raymond Novela
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09 Sep 18, Sally (South Africa - Summer rainfall climate)
Which varieties of onion can I plant in Johannesburg now. From seed
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Showing 41 - 50 of 88 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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