That's a puzzle. If they're in pots, maybe the soil is depleted of nutrients? Have you tried giving them a liquid fertilizer boost? The temperatures you describe should be GOOD for them, not cause them to flop.

They get what I think is adequate additional fertilizer to what they come planted with (Miracid or Rose Miracle Gro 1/2 strength every 3 weeks or so). Do you (or anyone) grow them and they stay upright until cold weather moves in? Since it seems to happen no matter where I've had them placed, I don't think it is shifting sunlight. But obviously I really don't have a clue about what's happening, just that throughout the years it seems to always be the same. A lot like Hostas. They start looking like poo about the same time as the Caladiums. I now know that with Hostas that's basically the nature of the beast...Thanks Donna...Maryl