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

Post a comment or question Display Newest first | Oldest first, Show comments for USA | for all countries
05 Mar 19, Carole (New Zealand - cool/mountain climate)
When is the best time to plant red onion seeds and what sort of fertilizer should I use do u use lime?
Reply or Post a new comment
06 Mar 19, mike (New Zealand - cool/mountain climate)
Best time to plant - read the top of the page. Fertiliser - one with not a high N content. Lime - read up about using lime.
Reply or Post a new comment
13 Feb 19, robert samuel walker (New Zealand - temperate climate)
when is the best time to put in red onion in christchurch
Reply or Post a new comment
14 Feb 19, mike (New Zealand - temperate climate)
You have worked out your temperate - looking under onions - it is in the calendar months near the top of the page.
Reply or Post a new comment
26 Nov 18, raymond (South Africa - Humid sub-tropical climate)
May I know, When to plant onions in an area of Bioresource Group no 1 (Moist Coast forest?) .My mom wants to plant it on a correct time. I ll be a great pleasure to know. Thanks. Raymond Novela
Reply or Post a new comment
12 Nov 18, John (New Zealand - temperate climate)
My onions growing in Napier are sprouting seed heads. Some are large seeming perhaps fully grown or close but some aren�t. Should I nip the heads and leave them or pull them immediately?
Reply or Post a new comment
13 Nov 18, Mike (New Zealand - temperate climate)
The onions that are big and going to seed need pulling out now. In fact any that are going to seed need pulling out now. Look up the internet for more info.
Reply or Post a new comment
11 Nov 18, Phil (Australia - temperate climate)
I usually grow brown onions which store well, however as we were running out I planted white ones as you can plant them earlier in the season. Now I have heaps of good sized white onions which have just started to run to seed, does anyone have good ideas on how to store them longer than a few weeks?
Reply or Post a new comment
13 Nov 18, Mike (Australia - sub-tropical climate)
From what I have read white don't keep as long as brown. Cure them in the sun for a week or so then keep in a cool dry place spread out - probably best to give some away.
Reply or Post a new comment
24 Oct 18, Michael Jones (Australia - temperate climate)
when do i plant cipollini onion seeds in west Australia
Reply or Post a new comment
Showing 161 - 170 of 374 comments
See comments for all plants

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.