Growing Onion

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

(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

16 Mar 21, David (South Africa - Summer rainfall climate)
I just transplanted some onion seedlings into a garden bed and it is March. Will they develop normally despite being planted early?
17 Mar 21, (South Africa - Summer rainfall climate)
You should be ok. Good idea to check planting times before buying/planting seeds or seedlings. You also have to consider your local conditions.
28 Feb 21, Barbara Esparza (USA - Zone 9b climate)
Are there any onion sets that I can plant in Texas zone 9b that are more heat resistant?
02 Mar 21, Anonymous (Australia - sub-tropical climate)
Plants generally have a temperature range that they grow in. That is why most crops are seasonal in a district. Try planting out of that range and you could fail.
22 Feb 21, Brett (Australia - sub-tropical climate)
If I was to plant brown onions, once harvested, how long will they last when they are stored in the pantry?
05 Mar 21, (Australia - sub-tropical climate)
Brown onions keep better than white onions. Let them harden off a bit after picking and keep in a cool aeriated area. Don't pack them tight - like in a bag.
26 Feb 21, Greg J (Australia - temperate climate)
Geelong Australia. I pulled up a couple of beds of brown onions in November. They've been hanging in the back shed since then, no problems at all. They're still as good as when I pulled them up, and we've been using them slowly. I think they will easily last 6 months or more.]
25 Feb 21, Brad (Australia - sub-tropical climate)
Depends on the variety of brown onion mate, the more pungent ones will store longer but they are more suitable to cooler areas. I'm sub-tropical too i'm from brisbane and I do a variety call "Texas early granno" I pulled about 70 to 80 out last year and none went bad. The trick is to harvest them when you need them. Green Harvest is a great site where I get most of my seeds from they are situated in south-east Qld and they have a lot of info of different varieties and the climates they are best suited for. Hope that helped Brett. -Brad
16 Feb 21, Judith c Greenleaf (USA - Zone 9b climate)
Can I plant onion sets in February or march? what sweet onion varieties do you suggest for No. Ca. marine zone 9B? Thank you.
17 Feb 21, Anonymous (USA - Zone 9b climate)
Consult the planting guide calendar and the footnote at the bottom of the page. If it says plant April and you plant Feb, the seeds/sets probably won't germinate/survive . There are reasons why it says to wait until April but take local conditions into considerations.
Showing 11 - 20 of 287 comments

Hi there, I planted white onions in May, they have not yet yellowed and the stalks have not fallen over- we're having a lot of rain fall early on and I am afraid they will rot if I leave them in the ground while it rains so much. Can I harvest them before they have yellowed or will they still mature correctly despite the rain? Any tips or advice would be much appreciated Thanks

- Kelly

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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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