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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02 Mar 21, (Canada - Zone 5a Temperate Warm Summer climate)
Start with good loose soil that has had some fertiliser, compost, manure put in it, don't over do it though. Water every day when small and then each 2 days when half grown. Keep weeded.
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03 Feb 21, Sky Kell (USA - Zone 7b climate)
Perennial onion that multiplies for 7b zone
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18 Dec 20, Sydney Thama (South Africa - Summer rainfall climate)
hello it is safe to plant onion around July and August?
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21 Dec 20, Anon (South Africa - Summer rainfall climate)
Go the onion page and check when to plant onions in your climate zone, or google and research about growing onions.
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13 Oct 20, Kelly (South Africa - Summer rainfall climate)
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
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16 Oct 20, (South Africa - Summer rainfall climate)
It says plant seed Feb Mar and you planted May, that is the problem. Check to see how big they are, if a good size pull out. You be the judge, keep an eye on them, if they look like going rotten out they come.
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13 Oct 20, Liesl Mittan (South Africa - Summer rainfall climate)
We planted onions late in march , they are ready and some are flowering .They should dry in the ground , but we are having rain. What do I do . Take them out and dry them hanging or leave in the ground and hope for hot weather . Thanks
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19 Oct 20, (South Africa - Summer rainfall climate)
Pull them out.
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10 Sep 20, Vicky (South Africa - Summer rainfall climate)
I planted red onion seedlings in April. I was waiting for the tops to bend over, as I've read. But now they're flowering. When should I have harvested? Also. The necks are very thick.
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11 Sep 20, (South Africa - Summer rainfall climate)
I don't grow onions but it says 24-34 weeks until harvest. It is probably time to harvest if they are going to seed. Pull out and allow to dry.
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Showing 101 - 110 of 366 comments
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Kate This happened to me too the first year I planted onions. Then after reading more I found that an onion grows to reproduce. It has two choices: 1. To flower. If it does then all it’s energy will pass from its bulb to the flower. Result no onion but a nice flower. 2. To form a bulb and wait for another year. This is what happpens when you bend the tops over and tie back the flower scape so it does not grow. When this is done, the onion stops putting energy into the flower and concentrates on forming a bulb. Then you get an onion. They are quite persistent so you will need to keep the tops bent over once the leaves start to brown. So plant as normal. Then when the tops start to brown bend them over and tie back the head so as to prevent or stop the flowering. https://garden.org/frogs/view/7543/

- David

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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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