Growing Onion

Allium cepa : Amaryllidaceae / the onion family

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

(Best months for growing Onion in USA - Zone 5a regions)

  • S = Plant undercover in seed trays
  • 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

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25 Oct 18, Mike (Australia - sub-tropical climate)
Read the guide here. Plant first half of the year - probably after Feb - summer probably too hot.
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18 Oct 18, Malcolm Langley (Australia - sub-tropical climate)
I planted onions last season and thined out where necessary and had a reasonable crop.this season l did it a bit differently. I planted the seeds into pots and then replanted into the ground so that I didn't waste any by thinning out. The seeds used were the from the same suppliers and were brown onions as before. This season they are growing well but most of them have very thick stems and seed pods are formed. The onionbulb in lots of instances is not developing .am l doing something wrong? Mal.
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23 Oct 18, Mike (Australia - temperate climate)
I had this problem this year. First time I had grown onions. I put it down to too rich a soil. Maybe less N applied. And probably back off the watering a bit when they have grown for say 4 mths.
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06 Oct 18, Wayne (Australia - temperate climate)
Onion Red Odourless: Planted sixty seedlings in April which have been growing well but are now going to flower and bulbs have not formed. (Adelaide Hills)
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07 Oct 18, Mike (Australia - sub-tropical climate)
I grew onions for the first time this year. Mixed success. White ones. Some formed bulbs some didn't - good health plants - probably too much N. Onions can take 6-8 mths to grow.
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09 Sep 18, Sally (South Africa - Summer rainfall climate)
Which varieties of onion can I plant in Johannesburg now. From seed
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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?
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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.
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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.
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12 Mar 18, Albert (Australia - temperate climate)
When do l plant a giant decorative allium and how deep.? any other advice would be appreciated.
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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. 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.
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