[Godhelm]

I already have onion seedlings on my plot - Ailsa Craig and North Holland Bloodred Redmate. This is as per packet/supplier instructions (they wnt in in November) as an experiment. If it works, great! If not, I will plant sets in Spring.

[devonbarmygardener]

OK, say I have a mass of onion seedlings, like a tub of grass - what do I do from then on?

I'm an onion set girl normally!!

[mumofstig]

If they are spaced out in the pots you can grow them on and plant them out individually like you do leeks, but not as deep - once the weather turns a bit warmer.

If they are very close together in the pots, you may have to pot them into modules so they have enough room to grow til they're planted out

[sunshineband]

Sow them more thinly to start with as that makes life easier tbh DBG 

I put one per module in for large onions and three per module - then plant them out in a small clump - for middle sized ones 

[ididntdoit]

"Can I grow red onions from seed in the same way?"

Yes, the obvious choice is Red Baron from seed and they do very well at a fraction of the price of sets. My experience when I have grown Red Baron sets and seeds at the same time is that the seed ones take a few weeks longer to establish but in the end both produce the same results.

[gavinjconway]

Aren't these onions that are already like grass a bit early? Onion seed should only be sowed end Dec / January ish... unless they are for showing.. 

[devonbarmygardener]

Mine were hypothetical grassy looking onions

[marcofez]

Always growing onions from seed! More choice, fairly easy to grow. Ailsa Craig and Bedfordshire champion done good for me. Have some other onion seeds to try as well. Even tried shallots from seed and will continue to do so.

[gavinjconway]

Mine were hypothetical grassy looking onions

maybe I should read and digest the posts before replying... Ooops...     

[devonbarmygardener]

Mine were hypothetical grassy looking onions

maybe I should read and digest the posts before replying... Ooops...     

Thats ok!

[Totty]

Got some "Ailsea" seed delivered today
Sowing tomorrow. Hopefully have 80(ish) giant onions in 8 months time!

Totty

[Kajazy]

I have pretty bad white rot on the plot, and have trialled onions side by side from sets versus from seed, and invariably the seed has been pretty successful, whilst the sets have been hit-n-miss.

I grow Golden Bear F1 onions from seed, to give them the best chance against white rot. For ease, I grow 'clumps' - i.e. about 4 or 5 seeds per module, then they get planted straight out like that.

[gavinjconway]

Got some "Ailsea" seed delivered today
Sowing tomorrow. Hopefully have 80(ish) giant onions in 8 months time!

Totty

I ordered some last night... they look a nice big onion..

[Nikkithefoot]

I have to admit to being a little frightened of growing onions from seed rather than set.  Apart from cost, is there another reason I should perhaps take a deep breath and go for it?

I have ummmm'd and ahhhhhhh'd about growing onions from seed and this year I bit the bullet and went for it.

Even though I was late getting the seeds in, sowed Feb 18th, I had 95 brilliant onions. They were a variety called Florence Long Red. They were harvested early Sept, so a little later than the set grown ones.

From the 100 sets I planted i possibly only got 60 ones of a remotely useful size, and some of those looked more like pickling onions.

On balance I'm not going down the set onion route again. Seed sown were bigger, more reliable and didn't seem to have the tendency to go to seed. Next year I'm going to grow white onions from seed as well.

One word of warning seed grown ones do seem to leave it until the very last minute to bulb up compared to the set grown ones, I had more than one or two sleepless nights thinking I would have loads of spring onions 

[Flowertot]

Ok so all the comments on this thread have made me much more keen to try growing onions from seed - but I am still nervous! The thing is that I don't have a proper greenhouse  just one of those plastic blow away 4 tier ones.  If I germinate the onions on a windowsill, would they be ok growing on in the plastic greenhouse until they are transplanted?