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

10 Feb 14, kathleen harris (Australia - temperate climate)
Can you recommend a variety of onion that I can grow for pickling. The pickling onions in the shops are too big and not nearly crisp enough.
07 May 14, Ted (Australia - temperate climate)
Kathleen we plant out cream gold for pickling have done it for years. Plant them close together rather thickly and harvest in summer. They can sit around for ages if needed before you pickle them. Very crisp.
06 Nov 13, doug Dewar (Australia - arid climate)
i have planted onions and spring onions over the top of pea mulch and a lot of seeds have germinated, i have been pulling them out as they come up and finally they have all gone.Should i use sulphate of potash to balance out the high level of nitrogen in the soil as i do not want to lose them because they take so long to grow,hoping you can help me,thanks doug dewar.
07 May 14, Travis Edwards (Australia - temperate climate)
If anything you will find that the decaying pea straw will be sucking nitrogen out of the soil while it is decaying once it has composted down well it will be nitrogen rich however. lime, and gypsum, would be a good additive as the decay process tends to be acid and onions prefer a slightly alkaline soil. (lime and gypsum will help neutralise the acidity.)
14 Nov 13, Norma (Australia - temperate climate)
I planted my red onions, in a patch where my beans were, they took twice as long to grow than my brown onions planted nearby in virgin soil, brown onions are almost the size of a Pomello, red onions are still coming on. Onions and pulses, beans and Peas) definitely are enemies
23 Oct 13, Anne (Australia - temperate climate)
what to do? my onions have developed flower stalks, it is mid-spring
27 Oct 13, Ferran (Australia - sub-tropical climate)
Are the onions ready to harvest? Could you harvest them? preventative ways to stop them putting their energy in to flowering are: cutting off the flower stalks, shading them, keeping them moist. Good luck!
13 Sep 13, Heather Sterling (South Africa - Semi-arid climate)
Having grown (and watered) white onions through this past Winter, I now find that the onions are going to seed before the bulb has fully grown out. It would be appreciated if you could give advice as to where I went wrong.
23 Oct 16, Chester Bosch (South Africa - Summer rainfall climate)
I have the same experience. Can somebody respond please.
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 291 - 300 of 368 comments

Onions are immortal and can be re-planted after harvest. When cutting for food, chop <1.5 cm from the roots for re-planting. Water well and the onion will bulb into a few new plants. Separate the bulbs and you will have a new batch of onions.

- Jase

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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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