Using a sunroom to overwinter begonias?
This year I fell in love with some begonias for the first time (Black Coffee, Last Laugh, Rex, and another unnamed) and they are doing great on my front porch...Well, now it is almost September and I would really like to be able to winter them in my sunroom, which I usually keep just barely heated except when I am using it, then I turn on the fireplace to bring it up to a comfortable temperature.
Will this work for begonias?
My plan is to group the plants near a baseboard heater that I leave on all winter, and put the pots in a pebbled tray for humidity. My concern is that it will get too cold, although it does stay above freezing and I have been able to winter other houseplants just fine... I just don't know about the begonias. They will get a lot of light, since the room has a south - west - north exposure. Is there a particular direction that would be best?
Any suggestions as to when to bring them in, location, fertilizing, expected leaf drop, or whatever would be very much appreciated. Two of my plants are pretty good size (about 2' leaf spread) and the other two are much smaller.
Thanks in advance
BettyLu in St. Louis