Raestr,
I didn't lift them until November this year
This could be the problem, Caladiums really hate the cold especially in combination with wetness! Not sure if that is the case in your area..
I have met them in their natural environment in the Atlantic Forest of Brazil, the summers there are wet and the cooler winter is the drier season...
I lost about half of my Caladium bulbs when I waited too long to lift the bulbs in my country, I think it was about mid or end October, when it gets chilly and wet with excessive rains.
This year I brought them in much earlier, about mid September with pot and all, no more watering and letting them go dormant, I didn't lose any, I have potted them up about a month ago in small pots, to later transfer them to bigger ones, they are all up and unfolding their first leaves. Of course they are in a heated room.. But in your case that might not be doable with so many bulbs..
The two previous winters during January-February I was travelling in Brazil and used another method as my house would be left unheated. I lifted the bulbs from their pots, let them dry out well and then stored them in a tin can with dry peat, I had also dusted them them with Cinnamon powder which is acting as a natural fungicide.
I gave the tin can to my brother to store in his house until I got back from my trip.
That did work quite well though I lost a couple of the smaller bulbs..
