Growing Onions from Seed in the Garden.
Traditionally onions are grown from sets, but vegetable gardeners have started to grow onions from seed, instead. One of the advantages of growing onions from seed is that the viral, bacterial and fungal diseases, that are usually carried over to the next crop on the bulbs, cannot survive in the seed. So onions grown from seed should be healthier.
Onion seed can be started off in modules in the spring & transplanted, or sown directly into the garden.
- seed depth - 1 cm
- germination time - 21 days
- distance between rows - 30 cm
- thin within the row so that 5 to 10 cm apart
Remove all thinnings from the vegetable garden, because the smell will attract Onion Fly. The thinnings can be eaten as spring onions in salads.
They are ready for harvesting from June to September. Each seed produces a single onion bulb.
To produce the best yield of well shaped bulbs it is important to thin the seedlings out.
Information on growing shallots from sets can be found here.
Onions are stored in the same way as shallots.
Thanks for the tips I just planted my seeds this week.
Comment by mike - March 3, 2008 2:26 am
Mike
Thanks for visiting! Good luck with the seeds
TopVeg
Comment by TopVeg - March 3, 2008 3:52 pm
I’m glad of this blog I didn’t have any idea how to grow onions from seed…I’ve only just planted my seeds
I’m not too fussed if they don’t succeed, but would like to do what I can to make them speed up growth (as I planted so late). Do you have any tips,and do you think they’ll be alright?
Comment by Ellie - May 10, 2008 10:49 am
Hi Ellie
You could cover your onion seedlings with a plastic sheet - or cloches - to help them along.
At this time of year you could plant a few onion sets, as they will grow better than young seedlings now.
Good luck!
TopVeg
Comment by TopVeg - May 10, 2008 6:14 pm
My husband has problems growing onions. He has tried with the sets, but the never get much bigger. He has put his seed this year one the windowsill in containers and they are popping up. What is the best way to put them into the soil how deep have they got to be-on top of the soil or just under. Hope you understand what I mean. Thanks Judith PS does the soil have to be of acid or alkali any suggestings will be gratefully received. 25th May 8.45 pm
Comment by Judith Duffy - May 25, 2008 5:37 pm
Hi Judith
Do you mean that he has sown seed instead of planting sets?
Seedlings
If so, the seed will have to be transplanted at the same depth it is now. If you make a hole in the seedbed with a pencil, hold onto the onion leaves and let the roots drop into the hole, so that the onion leaves are above the soil, as they are on the window sill. The bulb base should be 1/2″ below the surface.
Let the roots drop down freely into the hole. Gently press the soil around the roots, so they are snugly held in the soil. Make sure the soil around them is firm.
The seedlings should be transplanted 4″ apart with 9″ between the rows.
Before planting, apply a general fertiliser & rake the soil so it is reasonably fine and level. Tread it down to firm it.
Onions do not like acid soil, so add a bit of lime if yours is acid.
Hope that helps - TopVeg
Comment by TopVeg - May 26, 2008 7:45 am
have taken your advice and have had to write it down as pc is upstairs(dont’ ask) I will take your advice downstairs and hope that it works this time (onions) I thank you for your time. I will be back on to keep you informed. Thanks again Judith
Comment by Judith Duffy - May 26, 2008 1:01 pm
Judith
Remember to keep them moist - and water the onions well when you transplant them. The onion seedlings must not dry out.
Hope all works out for the one downstairs! Look forward to hearing how it progresses!
TopVeg
Comment by TopVeg - May 26, 2008 3:15 pm