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Growing Onion

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

(Best months for growing Onion in Australia - sub-tropical regions)

S = Plant undercover in seed trays. T = Plant out (transplant) seedlings. P = Plant in the garden.

  • 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 8°C and 30°C. (Show °F/in)
  • Space plants: 5 - 10 cm 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
  • Red onion
    Red onion
  • Young brown onion
    Young brown onion

Onions come in a range of colours and shapes and sizes. Brown :- strong flavour and pungent. Usually good keepers for storage. White :- milder but still flavoursome. Keep fairly well. Red :- Mild, suitable to use raw in salads and sandwiches. The seedlings should be allowed to gain a bit of strength before planting out - usually 4 to 6 weeks will be enough. When they are big enough to handle, you can plant out. They start off looking like blades of grass.

They don't have to be in a greenhouse (though that would be ideal), any sheltered spot will do. The idea is to guard against rapid changes of temperature, especially at night.

Onions can be bought as young plants (sets or seedlings) from garden shops/nurseries to plant straight into garden beds. Choose your variety according to your climate and the time of year as some onions will grow better in the cooler months .

Onion bulbs should sit on the surface of the soil. Do not cover. They will take six to eight months to mature. Onions are ready when the tops start to dry and fall over. Pull them and leave to dry for a few days. Store in a cool, dry airy place. Use a net bag or make a string by weaving the tops together.

Culinary hints - cooking and eating Onion

Brown onions roasted whole with other vegetables are delicious.
Red onions add colour to salads or stir-fry.

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.
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.
25 Feb 17, Eric ryan (Australia - temperate climate)
Can I grow onion in Hervey bay qld the sweet variety preferably
26 Feb 17, John (Australia - temperate climate)
Onions like a cooler climate but you could try Creamgold (Pukekohe) in late March or April for late spring/early summer harvest. As an alternative try shallots or potato onions. Onions don't like too much manure/fertiliser and need an open sunny spot with good airflow to avoid mildew problems. All the best.
20 Feb 17, michael kearns (Australia - temperate climate)
Which type of onion is better. brown or yellow
Showing 1 - 10 of 118 comments

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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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