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

18 Apr 17, gayle (Australia - temperate climate)
Hi...I have planted brown onion seeds in seed trays a week ago..they are sprouting...I was wondering when do I plant them in the vegetable garden. Also can I plant seed potatoes now (April) in Victoria. Thanks.
19 Apr 17, Giovanni (Australia - temperate climate)
Onion seedlings are susceptible to danping off so make sure they are in a well aired place. They can be transplanted as soon as they are large enough (2 or 3 leaves). The smaller they are the more attention they will need in the ground so wait a while, they will be easier to transplant and with less transplanting shock.
15 Apr 17, Jack (Australia - sub-tropical climate)
I've been looking for white onions for some time . Is there any reason for the short supply ?
15 Apr 17, Jo (Australia - temperate climate)
Do you mean white long-keeper, or white salad onions. Both types should be readily available on-line from companies like - New Gippsland Seeds, The Seed Collection, Diggers, Green Harvest and Eden seeds.
11 Apr 17, nik (New Zealand - temperate climate)
I planted 50 red onion seedling last year and they all split into 3 or 4 more like shallots, so after 6 months I gave up and pulled them out What went wrong ? there is no red shallot variety is there?
11 Apr 17, John (Australia - sub-tropical climate)
Onions are like daffodils and other bulbs in that they will grow extra bulbs as a form of multiplication. This can be caused by planting at the wrong time of the year for the variety. Check this on the seed packet and plant accordingly. Sadly nurseries sometimes sell 'out of season 'plants that look good. Tomatoes are a classic example with many plants sold after a few sunny days in late Winter or Early Spring. Trust this helps.
08 Apr 17, Sandra Millhouse (Australia - temperate climate)
Why are my brown onions growing up as spring onions?? I have even rung the company of the seeds and they sent me two new packets of seeds out. I planted some of them and they are still coming up as spring onions. Please help
11 Apr 17, David (Australia - temperate climate)
Onions take 4, 5 ,6 months to form the onion bulb. You may be expecting them too soon. I plant early Barletta onions March\April and Australian Brown, or Creamgold June to Sept. They look like spring onions until they form the bulb.
09 Apr 17, Giovanni (Australia - sub-tropical climate)
There are a number of reasons that could contribute to your problem with brown onions. 1. have you planted the right variety for the time of the year? Brown onion seed is normally sown in April or May. There a range of planting times for different types of onion. 2. Have you planted them too close? Onions will take some time before they 'bulb' out and may be still in the 'juvenile' stage. 3. Are they getting plenty of sun?. It is a difficult question to answer but as you have replanted seed it is not that. Trust this helps.
18 Mar 17, irene (South Africa - Semi-arid climate)
every i plant onion they dont come out what can i do plss help or tips.
Showing 211 - 220 of 371 comments

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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