I don't know what to suggest. I never would have recommended burying them under 4-6" of sandy soil to begin with. I would have assumed that would rot them ... but it didn't. I would also assume that uncovering them so suddenly and leaving previously-protected leaf tissue exposed to freezing nighttime temps would result in frost damage and potential rot .. and maybe it will. On the other hand, if you leave them buried there's a good chance that they won't bloom this year even if they do survive. So, I'm back to not knowing what to suggest.

That's one of the reasons I don't mulch my bearded irises. I don't have to worry about trying to figure out when to uncover them in the spring.

Laurie

Good answer Laurie.

We had lows in the 20's this winter (unheard of for this area & we're still digging up dead semi-tropicals) --- and the TBs were A-ok. But they had not been covered in any way.

Maybe no answer on the other forum because it's a tough question. Altho we are pretty nice here ;-)

Actually, I read IrisInTheGarden's query on the other forum, too, but didn't answer there because I didn't know what to recommend. ;-)

Laurie

I grow potted iris for sale, and overwinter them in the ground in pots covered by a couple inches of sandy soil. I just went out and uncovered mine. Our nightime temps get down to about 20. I haven't had a problem doing this early or late. They don't rot in the sandy soil. I would say uncover them now, and if it's predicted to be very cold, tip the pots on their sides and cover them with a blanket or whatever just for the night.

Spring is pretty cold and wet in New England and I assume Ontario. I'd dig them up so they drain well and put them in a semi-protected spot for a bit. I've never sunk beardeds in pots but I've sunk other things and I don't cover them. Just bury the pot to a tad about ground level.
Early mud season kills more iris here than the dead of winter.