Apparently this is a sign that the root cellar is too moist. (I’ve been so worried about the temperature being too high and I didn’t even think about the humidity level!) The carrots are sprouting — which will make them mushy — and the paper bags that the potatoes are in tear at the slightest tug.
The bottom of the fridge that we use for a root cellar (well, what would be the bottom if it were still a fridge, but which is now a side because it’s laying on its back in a hole in the ground) was missing when we rescued it from the garbage heap at the fairgrounds. We tacked some crap wood over it (not a typo — that’s what I call my scrap wood pile because so much of it is damaged and/or unusable) and called it good but that’s not doing anything to keep ambient moisture out.
For now I think I will move the carrots to what used to be the freezer compartment of the root cellar/fridge. The potatoes themselves seem just fine (hard as rocks) so I will try to devise a way of keeping them in the root cellar. The quick fix, of course, is just to put them in new paper bags (since I have no less than a dozen) but I think a better long term fix would be cloth bags (although those will need support to keep them upright and out of any water that might pool under the grate on the “floor”) or feed sack bags.
And next spring perhaps I will overhaul the root cellar into something more, you know, root cellar-ish. Something involving bricks or concrete blocks and a vent tube and whatnot. I’ll have to see what people are trying to jettison on Craigslist.