Growing Onion

Allium cepa : Amaryllidaceae / the onion family

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

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

  • S = Plant undercover in seed trays
  • T = Plant out (transplant) seedlings
  • 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

Your comments and tips

23 Oct 21, Judy (Australia - temperate climate)
My onions are starting to go to seed. Why has this happened, and what can I do about it?
05 Jul 21, Jacqueline (Australia - temperate climate)
I'm interested in planting red onions, I am growing spring onions, and leeks quite successfully but know nothing about red onion planting and care. Could you please advise me. I only have a small balcony style garden.
10 Jul 21, (Australia - sub-tropical climate)
All the onion family are pretty similar to grow. Plant them similar time as spring onions and leeks. If you want more info google
08 Aug 21, anne onn (Australia - temperate climate)
telling people to google something on a plant website is just lazy. @Jacqueline, you can safely plant the red onions as if they were spring onions, just allow for more space between the plants Note: Gardenate does not advise google - we assume that is how the questioner found our site)
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.
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.]
25 Feb 21, Brad (Australia - sub-tropical climate)
Depends on the variety of brown onion mate, the more pungent ones will store longer but they are more suitable to cooler areas. I'm sub-tropical too i'm from brisbane and I do a variety call "Texas early granno" I pulled about 70 to 80 out last year and none went bad. The trick is to harvest them when you need them. Green Harvest is a great site where I get most of my seeds from they are situated in south-east Qld and they have a lot of info of different varieties and the climates they are best suited for. Hope that helped Brett. -Brad
Showing 21 - 30 of 193 comments

Ask a question or post a comment or advice about Onion

Please provide your email address if you are hoping for a reply


All comments are reviewed before displaying on the site, so your posting will not appear immediately

Gardenate App

Put Gardenate in your pocket. Get our app for iPhone, iPad or Android to add your own plants and record your plantings and harvests

Planting Reminders

Join 60,000+ gardeners who already use Gardenate and subscribe to the free Gardenate planting reminders email newsletter.


Home | Vegetables and herbs to plant | Climate zones | About Gardenate | Contact us | Privacy Policy

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.
We cannot help if you are overrun by giant slugs.