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 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

16 Sep 19, Anon (Australia - sub-tropical climate)
What do you mean by sets?. I don't grow onions but I would think most people grow from seeds or seedlings.
27 Aug 19, Jessica (Australia - temperate climate)
Hi, can I still plant onion in September in Melbourne? thank you
27 Aug 19, Liz (New Zealand - sub-tropical climate)
Check here www.gardenate.com/plant/Onion?zone=2
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
13 Nov 19, anon (South Africa - Summer rainfall climate)
Pull apart.
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.
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.
28 Jul 19, Elizah Thadius (Australia - tropical climate)
Do we have an insecticide/fungicide for bulb onion? Can anyone tell me if there is any manufactured fertilizer for bulb onion?
29 Jul 19, (Australia - tropical climate)
Look up the internet to see if there is an insecticide/fungicide. The same as my comment for sweet potato. - learn what N P and K do for plants. Then apply that to what you are growing. They don't make different fertilisers for every kind of veggie.
16 Jul 19, Donna (Australia - temperate climate)
I'm confused I Googled what fertilizer is required for onions and 1 search says onions don't want a lot of nitrogen and another search says onions are nitrogen hungry. ...so which is it?
Showing 141 - 150 of 371 comments

Ask a question or post a comment or advice about Onion

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.