Help mold on my onion sets

Hi all started my sets around 3 weeks ago in 3” pots they have been in the un heated part of the greenhouse and as the pictures show they are growing quite well but have this mold on is this normal and any advice would be great as I have around 250 sets like it (2 white centurion and turbo and Red Baron)

 

Hi Notty, it looks like onion white rot in which case, like me, you're doomed! (Well your onions are.)
Nothing you can do about it but burn any infected. Don't plant out into the garden, white rot can remain in the soil for 8 years or more. Sorry.

 

It could be, but I’m not so sure? I thought white rot started from the base? If it were me, I’d ditch any that look dodgy and keep on the lookout for any others that look suspect. Don’t plant though until you’re sure they look healthy because once it’s in the soil, that’s it for quite a few years, the soil will be infected.

 

Pull one up and see if the mould is affecting the actual bulb.
Or is it just the brown outside skin beginning to rot in the damp compost.

 

I did pull one up and the first layer of skin fell of along with the mold the roots are very strong and about 2” long the bulb felt very firm and apart from the green mold they seem very healthy

 

Well I'm no expert on white rot, but to me it looks like mildew growing on the brown skins.

 

It is definitely green not white what can it do to see if it is mildew
Thanks for all the help everyone

 

Mildew is just my way of describing that kind of fungus, probably not technically Mildew as such, but looks like how the bread goes if you keep it too long.

 

Is there anything I can do or do I just bin the lot of them

 

If it were me, I’d bin the ones that are affected, the rest I would put outside during the day (weather permitting) to allow for some fresh air.

 

They all seem to have it any idea what I did wrong it was fresh multi purpose compost and only watered when felt dry

 

My guess would be lack of ventilation, which is why I suggested putting them outside.

 

Unless there’s a way of saving them then looks like new sets are needed

 

@pete , you reckon there’s anything he can do, considering they all have it?

 

I'd go along with your suggestion of moving them outside Freddy.
But keep them frost free.

I know I would not bin them if the mould is only surface mould and the bulbs are not soft and slimy.