Onion harvesting advice please

[Rosyred]

my set onions are the size of pickled ones and falling over the ones from seed are still green and up straight. Why do you think they didn't grow very big?

[Rosyred]

[mc55]

mine suddenly seem to have had a growth spurt over the last week, but I think they have a while to go yet.  Some are very small and didn't really get going, all were bought as sets from Wilkos - is this normal.

Its my first year, so I'm delighted with what I've got so far and hopefully next year will be better when the soil is a bit richer.