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

Post a comment or question Display Newest first | Oldest first, Show comments for USA | for all countries
17 Jul 19, (Australia - sub-tropical climate)
All plants need some nitrogen. Now if you put a lot of N on the onions, you would have a big green plant above the onion bulb and probably little bulb. N produces leaf and plant structure. Generally if you prepare your soil with compost manures etc and let it all rot in over 6-8 weeks with watering and digging it over, and maybe add a little general fert in the process then you would not have to fert the onions again. A general fert is sufficient to grow most things - look up and learn about crop rotation also.
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24 Jun 19, Cassie (Australia - cool/mountain climate)
And make sure you plant varieties that cope with your particular climate. Many varieties dont cope well with heat and will bolt to seed
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08 Jun 19, Ben Camenzuli (Australia - sub-tropical climate)
What is it that onions do not like as they grow ?? What is they like ? How to prevent onions going to seed ???
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10 Jun 19, (Australia - tropical climate)
Too much N. Water them. Pick them before they seed.
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24 May 19, Yvonne Hermann (Australia - sub-tropical climate)
I bought a large bag of salad(red) onions but due to unfortunate circumstances didn’t get use a lot of them. I now have approx 70 shooting onions. Can I plant these and will they produce new onions? How long from planting to harvesting & is now the right season in Queensland? Thanks in advance Yvonne
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18 Apr 19, SHIREEN WALTERS (South Africa - Summer rainfall climate)
Can I plant spring onions and coriander now (middle April) ?
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29 Apr 20, Allimuthu Perumal 0329443959 (South Africa - Summer rainfall climate)
Yes you can but try a tomato box size for coriander
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05 Mar 19, Carole (New Zealand - cool/mountain climate)
When is the best time to plant red onion seeds and what sort of fertilizer should I use do u use lime?
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06 Mar 19, mike (New Zealand - cool/mountain climate)
Best time to plant - read the top of the page. Fertiliser - one with not a high N content. Lime - read up about using lime.
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13 Feb 19, robert samuel walker (New Zealand - temperate climate)
when is the best time to put in red onion in christchurch
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Showing 151 - 160 of 371 comments
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two questions. Which variety of onions and garlic are best for growth in Puerto Rico. were can I buy them and expect to get them to Puerto Rico. Many say they are not to be shipped to Puerto Rico(price for living in the colony). Thanks, C.Foy

- Clifford Foy

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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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