Growing Onion

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

(Best months for growing Onion in New Zealand - cool/mountain regions)

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

02 May 21, Michele (New Zealand - cool/mountain climate)
I seem to have gotten white rot/fungus tha affects most onion varieties except spring onions- they will get it but very late on...does anyone know of a vigorous type of ordinary brown or red onion that might stave it off until I can harvest? Thanks.
10 May 21, Tony (New Zealand - temperate climate)
try spraying regularly with copper, also good for rust.
06 May 21, Anonymous (New Zealand - temperate climate)
Ring your local agricultural or agric company department about the fungus.
06 Apr 21, Duke Rick (USA - Zone 8b climate)
What is the best time to plant Maui onion seeds in my zone?
02 Apr 21, Debbie h. (USA - Zone 9b climate)
Can you plant onions that already have a green stem coming from it? Like ones in fridge if not used fast enough .
22 Jun 21, Jayne Matzkin (USA - Zone 9b climate)
I've done it. You take the outside layers off until you reach the layers the green stem is attached to and plug it in your garden. They become a bigger version of themselves. I see this a way of not wasting that onion and tossing it.
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?
Showing 11 - 20 of 297 comments

Ferolyn: The black (sharp) bits in the "pom-pom" are seeds. Yes you will get onions off them if you plant them. No, once the Onion has flowered it is pretty useless as an onion. Evelyn: day length sets teh onions "growing' it's bulb. you need the onion plant to grow in height BEFORE it grows its bulb else you end up with "sort of" spring onions. In canberra with heavy frosts probably better to wait til mid winter before planting. Graeme: timing is the key. If you live near the bay then you should be good to plant mid-late april (depending on the variety) this will allow the plant to grow before it starts bulbing (longer days). I planted Hunter River Browns today (West Sydney) so I am expecting a harvest of HUGE onions Nov-Dec

- David

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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. GardenGrow 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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