I don't know what's causing it.
I just use John Innes and grit which is kept outside. So the mix is damp enough and not much dust about really.

It's a bit better now. Might have been something else.
Thanks for the replies....

From the king of Lithops

https://www.bbc.co.uk/programmes/p08qn68n

It's an Opuntia of some sort, but it and the other cacti need a lot more light.
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Have you watered the pot now? I find seedlings can take ages to recover from rest. Once they start growing can't you just give them a bit more water than for more established plants? No, I haven't watered yet. But you're right, their only hope is water. These are fully developed seedlings, if you k...

Would it be foolhardy to re-bag a pot again this Spring? A pot that has been exposed and dried out over winter. Some of my seedlings are very small and I don't think they will survive. On the temperature swings mentioned above. I've modified my electrics to take this into account and we'll see how i...

I'm doing a bit of re-potting lately and over the years I think I'm seeing a correlation between re-potting and my eyes going mad itchy. I'd mostly have the door closed as it's a bit cool lately, so that probably doesn't help. But yesterday I was mostly just moving around plants and I'm dying again ...

A wooden floor?
I think that's a first for me.....

Just keep them moist until they get settled.
And make sure they are getting enough light at this time of year.

The Wiki page says: Propagation: Both commercially and in the home, propagation can be achieved by using short pieces of stem, one to three segments long, twisted off rather than cut. Cuttings are allowed to dry for 1–7 days, forming a callus at the broken end, and then rooted in an open growing med...

Is there any hardy succulent plants associated with graves and graveyards in the UK?