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Growing Onion

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

(Best months for growing Onion in South Africa - Summer rainfall 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
  • Red onion
  • Young brown onion

Onions come in a range of colours and shapes and sizes. Brown :- strong flavour and pungent. Usually good keepers for storage. White :- milder but still flavoursome. Keep fairly well. Red :- Mild, suitable to use raw in salads and sandwiches. The seedlings should be allowed to gain a bit of strength before planting out - usually 4 to 6 weeks will be enough. When they are big enough to handle, you can plant out. They start off looking like blades of grass.

They don't have to be in a greenhouse (though that would be ideal), any sheltered spot will do. The idea is to guard against rapid changes of temperature, especially at night.

Onions can be bought as young plants (sets or seedlings) from garden shops/nurseries to plant straight into garden beds. Choose your variety according to your climate and the time of year as some onions will grow better in the cooler months .

Onion bulbs should sit on the surface of the soil. Do not cover. They will take six to eight months to mature. Onions are ready when the tops start to dry and fall over. Pull them and leave to dry for a few days. Store in a cool, dry airy place. Use a net bag or make a string by weaving the tops together.

Culinary hints - cooking and eating Onion

Brown onions roasted whole with other vegetables are delicious.
Red onions add colour to salads or stir-fry.

Your comments and tips

23 Oct 12, jean Parsons (South Africa - Summer rainfall climate)
What is the best cultavar for picking and does it make a differance.
26 Dec 12, Ronel (South Africa - Summer rainfall climate)
Looking for help, I am looking for seeds of the Egyptian Walking onion, also known as the Tree onion, Winter onion or Top onion. Please can anyone help.
06 Jan 13, liyungu mulikita (Canada - Zone 2b Sub-Arctic climate)
hi there,you people are doing a great job on lessons on how to grow onions.
17 Jan 13, solly (South Africa - Summer rainfall climate)
Need to plant brown onions now, is it the right time? How much water do onions need? How much fertiliser and when do i put it?
29 Jan 13, Conradt (South Africa - Summer rainfall climate)
I sow the onions in late January to early March, I prepare a patch in the vegetable garden for this. The stand where the onions will be transplanted to can be prepared in the mean time, If your soil is very heavy, sand can be worked in, as well as gracious amounts of organic fertilizer and ash (from your wood braai) This method give you time to ensure your bed is light and rich when your onions is ready to be transplanted around April. I use a clear plastic covering during coldest of winter months, just to keep the frost off. Hope this help.
23 Jun 13, Ann Bye (South Africa - Summer rainfall climate)
I have onions that are starting to sprout. Can I plant them now or is it too early. Live in Gauteng so still a lot of frost.
01 Aug 13, Marietjie (South Africa - Summer rainfall climate)
Can I sow onions, texas grano, now? Living in Potchefstroom.
19 Aug 13, Aldo (South Africa - Semi-arid climate)
Hi all, I dont have a lot garden space and was wondering if it is possible to plant them in containers? Regards
20 Aug 13, JIM (Australia - temperate climate)
hi I grow spring onions in a foam box & have never had them grow better don't pull them out just cut off the leavses they will replentish themselves for years & no trouble with snails or grubs,
20 Aug 13, Rui (South Africa - Summer rainfall climate)
Sometimes my bought onions in the kitchen start growing leaves. Can I plant these onions, and if so, will it spread and will other onions grow from it, and how should I plant them? Or can you only grow onions from seeds? Thank you.
Showing 1 - 10 of 50 comments

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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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