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

02 May 18, TJ Russell-Zapata (USA - Zone 7a climate)
I am moving to zone 7a from Texas. Do I still over winter garlic and onions?
23 Mar 18, Fanie Zulu (South Africa - Summer rainfall climate)
Good day, can I plant the Australian brown onion throughout the year in South Africa? I want to maintain the monthly supply for my customers.
23 Apr 18, hennie (South Africa - Summer rainfall climate)
typically root vegetables such as onions,carrots and beetroot can be grown year round , just ensure they have enough deep soil , and keep an eye on the moisture levels, after the bulbs started forming , and give them ample space between each plant , thinning is an essential function.
12 Mar 18, Albert (Australia - temperate climate)
When do l plant a giant decorative allium and how deep.? any other advice would be appreciated.
13 Mar 18, Mike (Australia - tropical climate)
Type into google
10 Mar 18, Nana (South Africa - Summer rainfall climate)
I live in Lady Frere, Eastern Cape S.A. I would like to know if I can plant onions now in March. Also how long will they take to mature.
02 Mar 18, Leigh (New Zealand - temperate climate)
Hi, I’m having fun growing potatoes, Kumara and even sweetcorn that have sprouted in the bottom of my pantry. Wondering if the same should work with a brown onion that has sprouted greens out of the top?
22 Feb 18, Trevor Smith (New Zealand - temperate climate)
If I was to sow seeds in February and plant out in say May would frosts have any adverse effect on them?
22 May 19, Mark Taylor (New Zealand - temperate climate)
Onions are hardy plants and so frost tolerant, they will survive the winter. My understanding is If you plant them in Autumn you can harvest them in spring as spring onions but you won't get bulbs. They need to be planted in the spring for them to develop into onion bulbs. This is because bulb formation only starts after the summer equinox when the days start to shorten.
26 Feb 18, Mike (New Zealand - temperate climate)
If you sow now you would transplant in 6-8 weeks. I think onions can handle some frost. Check on the net about this.
Showing 171 - 180 of 368 comments

with the green shoot just out of the ground - bulb covered with soil. Do not over water or you will have mush.

- Karen

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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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