No it doesn't come back, which is why some shouldn't ever be handled, as you've found out. It doesn't really hurt them, except aesthetically. I'd get your brother to sift top dressing or something else useful to you. The words you can use for this are 'glaucous' or 'farinaceous'.

Called bloom or pruinose it is used to slow down evaporation. Normally, in cultivation it should not be an issue but I can't speak of plants in your climes. I'm not sure how much it prevents sunburn.

tj

The plant will not replace the farina (the dust). The farina helps protect the plant from the direct sun. It is not fatal to remove it, but it does change the looks of the plant and certainly does not help it.

I had to scrub a plant covered with honeydew from aphids and it removed the farina. I was really afraid I had killed it, but I protected it from direct sun and it did fine and I finally returned it to full sun. It just didn't look the same until new growth covered where I had scrubbed.

(Blue - I'd clobber my brother! But we've had our fights for years - like all siblings! I'm 62 and we still go at it on occasion. LOL)

Bugger. Okay. Well, it still looks pretty, the colours just aren't as pale, and won't be for a while I suppose. It's been in full sun since I got it a few weeks ago, only really brought it in when we've had a lot of rain.

Thanks for the advice guys.

Crenda - I was tempted to clobber the bloody kid lol. To be fair, he was only trying to help, but I think until he learns how to look after his mint plant (Which he has almost killed...twice...) he should stay away from my succulent/cactus babies. XD

Why would he be rubbing the lovely glaucous coating off, anyway?

Christopher

probably thot it looked dusty ...

I have no idea Christopher. It probably was because he thought it looked dusty, but I'll ask him when he gets home from school. I unfortunately don't have any photos of it before my brother took to it (that show the sides of it at least), but this is the lil' guy now.

Blue

You and it will be OK - that particular one doesn't depend much, if at all, on its degree of farinaceousness to fend off sunburn.

Indeed, I didn't know this one had a coating in the first place. You have a nice plant there.

Christopher

"Because I wanted the plant," he says. Brothers XD

So it's not a dust, but a wax. Interesting, and good to know.

Thankyou all for the help. :)

Blue.

my blue hostas get that on the undersides of the leaves, and there is also a 'waxy' coat on the front of the leaves. That coating can 'melt' if it gets too much sun ...