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

08 Apr 21, Anon (USA - Zone 4b climate)
Put the question into google and it will explain how to do it.
25 Mar 21, Jean (Australia - temperate climate)
My onion bed is prepared with plenty of chook poo, and top soil containing sheep and cow manure..plus lime and water retaining dressing.. Are there any other element missing or anything l'm putting on that is not necessary.? Why do the onions have thick necks? Am I leaving the onions too long before harvesting when seed stalks appear? I would appreciate your advice. I live in Lake Clifton 6215 WA on sandy soil which we are building up with compost and manures , lime etc
26 Mar 21, Anonymous (Australia - sub-tropical climate)
Onions don't need really rich soil, as in heaps of nitrogen. They are a bulb and need Phosphate. With the sandy soil better to build it up with mulchy compost, it can have a bit of chicken/sheep/cow manure in the compost. Or at the end of your growing season add manures grass clipping leaves etc to your soil and turn it and water (rain hopefully) during your fallow time, If you do that over 3-4-5 months then you should have really good soil to start with. You may need to add some lime to balance the soil ph back to 6-7. If you have big thick leaves stalks that means too much nitrogen.
16 Mar 21, David (South Africa - Summer rainfall climate)
I just transplanted some onion seedlings into a garden bed and it is March. Will they develop normally despite being planted early?
17 Mar 21, (South Africa - Summer rainfall climate)
You should be ok. Good idea to check planting times before buying/planting seeds or seedlings. You also have to consider your local conditions.
28 Feb 21, Barbara Esparza (USA - Zone 9b climate)
Are there any onion sets that I can plant in Texas zone 9b that are more heat resistant?
02 Mar 21, Anonymous (Australia - sub-tropical climate)
Plants generally have a temperature range that they grow in. That is why most crops are seasonal in a district. Try planting out of that range and you could fail.
22 Feb 21, Brett (Australia - sub-tropical climate)
If I was to plant brown onions, once harvested, how long will they last when they are stored in the pantry?
05 Mar 21, (Australia - sub-tropical climate)
Brown onions keep better than white onions. Let them harden off a bit after picking and keep in a cool aeriated area. Don't pack them tight - like in a bag.
26 Feb 21, Greg J (Australia - temperate climate)
Geelong Australia. I pulled up a couple of beds of brown onions in November. They've been hanging in the back shed since then, no problems at all. They're still as good as when I pulled them up, and we've been using them slowly. I think they will easily last 6 months or more.]
Showing 91 - 100 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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