Growing Onion

Allium cepa : Amaryllidaceae / the onion family

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

(Best months for growing Onion in New Zealand - cool/mountain 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

25 Oct 16, Trish (Australia - temperate climate)
Hi - I want to use the seed from my onions to plant for the next round. How should I do this?
27 Oct 16, Tempest (Australia - temperate climate)
Leave your best/biggest onion(s) to go to seed. It may take a while, but it's worth it to have all the extra seed. My friend did this but wasn't able to harvest the seed when it was ready - she now has lots of onions popping up around the original onion. Best excuse for less effort! ;)
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
10 Jul 16, Cassie (Australia - cool/mountain climate)
So why did my onions grow well then split and sprout? They have no intention of having their tops die back. Previously I've had them go to seed and clearly avoid the whole 'tops dying back' thing too. I sow seed in late winter and plant out the seedlings in early spring. What am I doing wrong?
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
18 Jun 16, Christine (Australia - tropical climate)
I have onions shooting in the vegie bin. My son said when I plant them I have to put the new growth above the soil, but I though this was the root. Which way do I plant them please?
01 Jul 16, Barb (Australia - temperate climate)
Your son is right - the green shoots are the stems/leaves starting to grow. So plant these uppermost. I find the ones that I grow from shooting onions may not bulb up properly. but they make great spring onions, and if left will divide so you'll have a little patch of spring onions.
01 Jun 16, Annie (Australia - cool/mountain climate)
In regards to soil temp for onions. You suggest 8-30 degree temps are best but my app is saying plant in garden now, (Natone, Tas) We are currently getting 2-15 degrees on average and dropping with morning frosts. Will onions survive or do they need to go into the hothouse?
26 Jun 16, stephen kettle (Australia - cool/mountain climate)
Hi Annie, I'm in Latrobe, and I've always planted onions out on , or around the shortest day
25 May 16, Colin Campbell (New Zealand - temperate climate)
I planted onion seedlings 2 months ago. They all look healthy but I am concerned at the length of the tops--up to 30cm--which is causing some lifting of the bulb. Should I trim the tops back or leave as is? Your advice would be appreciated. Thank you.
Showing 241 - 250 of 368 comments

hi i live on the gold coast Queensland . i have planted my onion 2 weeks ago in the cloudy times .ok .then we hit harsh sun times .i had to cover and they are ok growing well .if u just leave them in the sun they fry .....my second batch i lost maybe half my crop ...

- marco

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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. GardenGrow 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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