Black sooty mould on onion leaves

[ameno]

I was just up at the allotment and noticed that a lot of my onion leaves are looking rather sickly, with black sooty mould on them. I've never encountered this before.
They're pretty much ready, anyway, so the loss of the leaves is no big deal, but I'm concerned it might spread to the bulbs and rot them in storage.
What do you recommend? Cut off the leaves and dig them now? Or maybe just cut off the leaves and then leave then in situ for a bit longer?

[veggiechicken]

Is this it? https://www.rhs.org.uk/advice/profile?PID=743

[SarrissUK]

Sounds like black mold. Just dry well before storing, and keep it ventilated well as that will help it not spread more. I've only had it once and I didn't have enough onions to need to store them for very long. There may be someone else along with better advice!

[ameno]

Is this it? https://www.rhs.org.uk/advice/profile?PID=743

No, it's not downy mildew.
There's no white growth at all, and the spores are definitely black, not purple.

Sounds like black mold. Just dry well before storing, and keep it ventilated well as that will help it not spread more. I've only had it once and I didn't have enough onions to need to store them for very long. There may be someone else along with better advice!

Dig them now? Or just cut off the tops and leave the bulbs to dry in situ?

[Scarlet]

Have you got any photos? Are you sure it's only the leaf that has the problem? Have you inspected any of the bulbs?

[ameno]

Have you got any photos? Are you sure it's only the leaf that has the problem? Have you inspected any of the bulbs?

Yeah, the bulbs are absolutely fine, for now, at least.
I've decided to cut off the leaves and loosen the roots today, then dig up entirely in a few days time, when they have dried off a bit more.

[ameno]

Well, I've cut off all the tops and dug them up, leaving them on the soil to dry for a few days. The tops have all gone in the bin, just in case.
Three of the bulbs had a bit of basal rot (caused by Fusarium, apparently), so I've brought them back for immediate consumption, but the others bulbs all look fine: firm and undamaged. Pretty big, too, considering I didn't plant them until the 5th of May, and the sets were miniscule.
I also discovered that I have one red onion in the bunch. Must have gotten mixed up with the other sets by mistake.

[SarrissUK]

Yes, sorry - I meant to say, pull them up and dry them. That's what I was advised by the old fellas at my site when I got black mold on my onions.