Growing Onion

Allium cepa : Amaryllidaceae / the onion family

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

(Best months for growing Onion in South Africa - Summer rainfall 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

Post a comment or question Display Newest first | Oldest first, Show comments for South Africa | for all countries
07 May 17, (Australia - sub-tropical climate)
Hello Jimmy, We need a bit more information. Do you want to sell the onions while they are small or when they are larger, before the tops die down. You can sell or eat onions at any stage but if the tops have not died down they will not keep very long.
Reply or Post a new comment
22 Apr 17, Keikantseng (South Africa - Summer rainfall climate)
I an staying in Taunton village in North west province. Can I plant onion in April?
Reply or Post a new comment
23 Apr 17, John (Australia - temperate climate)
Yes you can. Long Keeping varieties can be sown now.
Reply or Post a new comment
18 Mar 17, irene (South Africa - Semi-arid climate)
every i plant onion they dont come out what can i do plss help or tips.
Reply or Post a new comment
21 Mar 17, John (Australia - temperate climate)
Onions are generally fairly easy to germinate. They need to be planted about 3 times their diameter with soil. A good way to do this is to sprinkle the seed over a small area that has been broken up and is very fine then cover with some more fine soil. Keep the soil damp but not wet. When the seedlings emerge they will be very fine like a needle. keep them damp but not wet as they may get fungus problems. A spot that gets some sunshine and a bit of airflow is good. They will take about 4-6 weeks before they are ready to transplant into rows in the garden. They will take about 6 months to be ready to harvest and store (when the tops flop over and start to dry). I hope this helps. Don't hesitate to ask questions, we are here to help.
Reply or Post a new comment
19 Nov 16, Atholl Selkirk (South Africa - Summer rainfall climate)
Where can I purchase onion sets in South Africa, Gauteng?
Reply or Post a new comment
17 Oct 16, nompumelelo (South Africa - Semi-arid climate)
what is the best growing season for onions in KwaZulu Natal, South africa e.g feb-march? and ehat are the heat unit requirements
Reply or Post a new comment
08 Jul 16, Andrew (South Africa - Summer rainfall climate)
is it possible for me to grow onion in summer and which variety of onion can strive better
Reply or Post a new comment
19 Feb 16, Nico (South Africa - Semi-arid climate)
What variety will be ideal for South Africa, semi arid I believe you are not able to plant Australian Brown south of a certain latitude?
Reply or Post a new comment
17 Mar 16, Bee-Pie (South Africa - Summer rainfall climate)
Texas Grano
Reply or Post a new comment
Showing 61 - 70 of 88 comments
See comments for all plants

(FROM THE NET) Manganese and zinc deficiencies are the most common ONION problem that causes tops to prematurely bend over OR become disfigured....Tops falling over prior to the bulb reaching maturity can result in decreased yields Young plants are particularly sensitive to Zn deficiency..... Problems are more common on high pH or calcareous soils or during cold, wet weather.... I suggested adding poultry manure (chicken manure) -- poultry manure tends to be high in Zinc, in a well balanced way. .Zinc also exits naturally in rocks. The amount of zinc present in the soil depends on the parent materials of that soil. Sandy and highly leached acid soils generally have low plant available zinc. Cool soil temperatures in early spring can intensify the need for zinc. Root growth is also stunted by cool temperatures and reduces the plant’s ability to find new sources of zinc in the soil profile. Also note: -onions and other alliums need more phosphorus and potassium than most other vegetables. They also need more copper, manganese, zinc, and molybdenum. Also please be aware that : There is a known relationship between phosphorus and zinc in the soil. Excessive application of phosphate fertilizers can caused zinc deficiencies. A phosphorus-induced zinc deficiency is a concern and may occur only if very high rates of phosphate fertilizer (more than 200 lb P2O5/acre) are used and the soil has zinc levels is in the range between Low and Very Low.

- Celeste Archer

Please provide your email address if you are hoping for a reply


All comments are reviewed before displaying on the site, so your posting will not appear immediately

Gardenate App

Put Gardenate in your pocket. Get our app for iPhone, iPad or Android to add your own plants and record your plantings and harvests

Planting Reminders

Join 60,000+ gardeners who already use Gardenate and subscribe to the free Gardenate planting reminders email newsletter.


Home | Vegetables and herbs to plant | Climate zones | About Gardenate | Contact us | Privacy Policy

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.
We cannot help if you are overrun by giant slugs.