[rowlandwells]

I know the topic of onions has been discussed on site many times but I'm not quite sure about my overwintering onions possibly due to the cold winter conditions they seem to have stopped growing some where sowed as seed and some sets in pots but as I said both have basically stopped growing there in the poly tunnel not heated but having said that its not as cold as the greenhouses

the compost does seem dry and I'm not sure if i should water them from the top or bottom there sitting in drip trays and i did notice I have lost some to that fungal disease so any advise would be most welcome

[New shoot]

They do stop growing during colder weather and sit the winter out without doing too much. 

As to watering, if they are in trays, I would say water from the base.  Start with just a little water and then you can always add more if you feel they are still dry. 

[rowlandwells]

many thanks new shoot

[Goosegirl]

When watering anything in pots or trays I always go by testing them by weight. If they feel lighter than when potted they need a bit of water.