Onion sets

^^^ Thanks Can, you've given me an idea.
I've never had much luck with onions - they seem to sit in the ground for months and come out the same size as the sets that were planted! Perhaps I should try planting some sets in the GH in the soil around the bottomless tomato pots. The onions would benefit from the tomato feed and be watered regularly, unlike outdoors. Also, maybe the onions would act as a deterrent to the whitefly which has plagued the GH this year.
The soil in the beds is not very deep, 3-4 inches but, since the onions sit at the top of the soil this may not be a problem.

Any advice and opinions welcomed!!

They've got two chances. You'll, quite rightly, still give it a try even if we all say dont bother. Personally I think it's a brilliant idea.