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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 in same bed): Lemon Balm, Borage, Carrots, Beets, Silverbeet, Lettuce, Amaranth
  • Avoid growing in same bed: 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

01 Feb 17, Grace (Australia - temperate climate)
I'm looking at onions. Temperate area. Cohuna vic. What isnthe difference between the "transplant seedlings" and "plant in garden"? Hmmm. Or does the "plant in garden" mean I can plant seed straight into the garden instead of growing them now in seed trays?
04 Feb 17, John (Australia - temperate climate)
Any seeds planted directly into the garden will do better than transplants because they don't get any transplant shock. Having said that it is not easy to sow onion seed far enough apart to achieve this without thinning. Seed sown directly into the ground in friable soil will do a lot better than tray grown seedlings generally because moisture is easier to keep more consistent. these can then be transplanted. Trust this helps and is not too confusing.
29 Jan 17, Anthony (Australia - temperate climate)
I am keen on growing brown onions at home in Sydney..i have been reading up on onions and found that there are long day short day and intermediate day varieties...which verity best suits Sydney this winter and even next summer...Also whats the best variety of onion that best suits Sydney....Im near Parramatta... Also where would the best place to get seeds for this variety of onion... Thankyou....
04 Feb 17, John (Australia - temperate climate)
We are south of Sydney but I think it would be about the same. Check the seed packets or catalogue when purchasing. Feb-Mar - Early White Barletta, Erly Flat White (salad onion) Apr-May - Golden Globe, Hunter River White, Hunter River Brown, Gladalan Brown Apr-Jul - Odourless, Calred (Californian Red), Pearl Pickler May-Jul - White Spanish, Australian Brown, Brown Spanish Jun-Jul - Pukekohe (Creamgold) Jul-Sep - Ailsa Craig, White Spanish, All Year - White Lisbon, Long White Bunching (spring onion) I am indebted to Norman de Vaus for this information. He has a seed company called New Gippsland Seed Farm which you should be able to find on the internet. Trust this helps.
04 Feb 17, John (Australia - temperate climate)
We are further south than Sydney but the following list should be a good guide for you. Also check the packet or seed catalogue for what is right for Sydney when purchasing. Feb-Mar - Early Flat White (salad onion), Early Barletta Apr-May - Golden Globe, Hunter River White, Hunter River Brown, Gladalan Brown Apr-Jul - Odourless, Calred (Californian Red) May-Jul - White Spanish, Australian Brown (Brown Spanish) Jun-Jul - Pukekohe (Creamgold) Jul-Sep - Ailsa Craig, Prizetaker, White Spanish All Year - Long White Bunching - Spring onions (thin like a pencil) These are seed sowing t
15 Jan 17, PAUL DZIADULEWICZ (Australia - temperate climate)
BROWN ONIONS GROWN IN OUR VEG PATCH HAVE NO TASTE AT ALL. THEY LOOK GREAT, ARE A GOOD SIZE AND APPEAR TO BE HEALTHY CAN YOU OFFER ANY SUGGESTIONS? CHEERS PAUL
16 Jan 17, John Mauger (Australia - temperate climate)
Hello Paul. There could be a number of reasons for your problem. 1. Are the onions ripe? When onions are ready for harvest the tops will have died off and will be lying flat on the ground. 2. Were they 'salad' or 'long keeping' onions? Salad onions are flat and very mild flavoured. What was the variety and its description? Brown or White Spanish onions are much hotter than mild varieties such as' Creamgold' or' Pukekohe'. This may not solve the problem for your current crop but trust it will give you some answers for the next one.
02 Jan 17, Bob (Australia - temperate climate)
I'm in Sydney NSW, and I think I'm in the temperate zone. is that correct Cheers
03 Jan 17, John Mauger (Australia - temperate climate)
Sydney would be temperate but you can grow a lot of subtropical things there as well. A lot of Sydney does not get frosts.
10 Dec 16, John (Australia - temperate climate)
I would like to grow some red onions I can not find seeds but I brought some bulbs from the local green grocer now do I plant the bulb in the garden or do I keep them in the cupboard or fridge till they spout I live in Tasmania
Showing 1 - 10 of 107 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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