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
25 Oct 16, Trish (Australia - temperate climate)
Hi - I want to use the seed from my onions to plant for the next round. How should I do this?
Reply or Post a new comment
27 Oct 16, Tempest (Australia - temperate climate)
Leave your best/biggest onion(s) to go to seed. It may take a while, but it's worth it to have all the extra seed. My friend did this but wasn't able to harvest the seed when it was ready - she now has lots of onions popping up around the original onion. Best excuse for less effort! ;)
Reply or Post a new comment
17 Oct 16, nompumelelo (South Africa - Semi-arid climate)
what is the best growing season for onions in KwaZulu Natal, South africa e.g feb-march? and ehat are the heat unit requirements
Reply or Post a new comment
10 Jul 16, Cassie (Australia - cool/mountain climate)
So why did my onions grow well then split and sprout? They have no intention of having their tops die back. Previously I've had them go to seed and clearly avoid the whole 'tops dying back' thing too. I sow seed in late winter and plant out the seedlings in early spring. What am I doing wrong?
Reply or Post a new comment
08 Jul 16, Andrew (South Africa - Summer rainfall climate)
is it possible for me to grow onion in summer and which variety of onion can strive better
Reply or Post a new comment
18 Jun 16, Christine (Australia - tropical climate)
I have onions shooting in the vegie bin. My son said when I plant them I have to put the new growth above the soil, but I though this was the root. Which way do I plant them please?
Reply or Post a new comment
01 Jul 16, Barb (Australia - temperate climate)
Your son is right - the green shoots are the stems/leaves starting to grow. So plant these uppermost. I find the ones that I grow from shooting onions may not bulb up properly. but they make great spring onions, and if left will divide so you'll have a little patch of spring onions.
Reply or Post a new comment
01 Jun 16, Annie (Australia - cool/mountain climate)
In regards to soil temp for onions. You suggest 8-30 degree temps are best but my app is saying plant in garden now, (Natone, Tas) We are currently getting 2-15 degrees on average and dropping with morning frosts. Will onions survive or do they need to go into the hothouse?
Reply or Post a new comment
26 Jun 16, stephen kettle (Australia - cool/mountain climate)
Hi Annie, I'm in Latrobe, and I've always planted onions out on , or around the shortest day
Reply or Post a new comment
25 May 16, Colin Campbell (New Zealand - temperate climate)
I planted onion seedlings 2 months ago. They all look healthy but I am concerned at the length of the tops--up to 30cm--which is causing some lifting of the bulb. Should I trim the tops back or leave as is? Your advice would be appreciated. Thank you.
Reply or Post a new comment
Showing 241 - 250 of 368 comments
See comments for all plants

Since you are having problems with your Texas Grano -- I would recommend going to an Egyptian walking onion (or other walking onion). Video abojut the onion can be found here: https://www.bing.com/videos/riverview/relatedvideo?q=walking+onions&mid=17F7CAB6E4A914745E4A17F7CAB6E4A914745E4A&FORM=VIRE Additionally: the walking onion originated from a cross between the Welsh onion (Allium fistulosum), and the common onion (Allium cepa). The Egyptian walking onion, Allium x proliferum, is a member of the allium family and a great addition to the perennial vegetable garden. Egyptian onions go by many names, including tree onions, topset (or topsetting) onions, and walking onions. The seeds are slow growing, and can take several years for them to grow and flower. That’s why people grow them mostly from established bulbs. Every part of the Egyptian walking onion is edible, including the bulb in the ground, the stems, the flower, and the aerial bulbils. There are different varieties -- some zones 3-9 others 3-10. I would select a 3-10 for your area -- additionally some types grow substantial bulbs under ground -- others have small underground bulbs -- so select your variety based on your need. There are white, brown and purple walking onions. There is also the RED CATAWISSA WALKING onion -- which is not classified as an Egyptian walker -- but is still a walking onion: this variety for its larger sized bulbs and topsets that are much larger than the typical walking onion. All parts of the plant are edible. Walking onions are a standard choice for permaculture gardens and food forests -- they are very low maintenance - and very reliable -- so a good choice for anyone having difficulty growing regular onions.

- Celeste Archer

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.