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

06 Oct 18, Wayne (Australia - temperate climate)
Onion Red Odourless: Planted sixty seedlings in April which have been growing well but are now going to flower and bulbs have not formed. (Adelaide Hills)
07 Oct 18, Mike (Australia - sub-tropical climate)
I grew onions for the first time this year. Mixed success. White ones. Some formed bulbs some didn't - good health plants - probably too much N. Onions can take 6-8 mths to grow.
09 Sep 18, Sally (South Africa - Summer rainfall climate)
Which varieties of onion can I plant in Johannesburg now. From seed
02 May 18, TJ Russell-Zapata (USA - Zone 7a climate)
I am moving to zone 7a from Texas. Do I still over winter garlic and onions?
23 Mar 18, Fanie Zulu (South Africa - Summer rainfall climate)
Good day, can I plant the Australian brown onion throughout the year in South Africa? I want to maintain the monthly supply for my customers.
23 Apr 18, hennie (South Africa - Summer rainfall climate)
typically root vegetables such as onions,carrots and beetroot can be grown year round , just ensure they have enough deep soil , and keep an eye on the moisture levels, after the bulbs started forming , and give them ample space between each plant , thinning is an essential function.
12 Mar 18, Albert (Australia - temperate climate)
When do l plant a giant decorative allium and how deep.? any other advice would be appreciated.
13 Mar 18, Mike (Australia - tropical climate)
Type into google
10 Mar 18, Nana (South Africa - Summer rainfall climate)
I live in Lady Frere, Eastern Cape S.A. I would like to know if I can plant onions now in March. Also how long will they take to mature.
02 Mar 18, Leigh (New Zealand - temperate climate)
Hi, I’m having fun growing potatoes, Kumara and even sweetcorn that have sprouted in the bottom of my pantry. Wondering if the same should work with a brown onion that has sprouted greens out of the top?
Showing 171 - 180 of 371 comments

two questions. Which variety of onions and garlic are best for growth in Puerto Rico. were can I buy them and expect to get them to Puerto Rico. Many say they are not to be shipped to Puerto Rico(price for living in the colony). Thanks, C.Foy

- Clifford Foy

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.