Tuberous begonias require winter dormancy, so don't try to grow it all winter indoors. You can wait till the first light frost has zapped the leaves, or you can cut the leaves off and bring it in for storage. Personally, I'm waiting for the frost.

Janet's Garden

janetr - have you had much luck overwintering them? Every time I try they don't make it - they dry out too much. I suspect it's too warm in my storage area during the fall - it's cool enough in the winter, but it's usually late December before the temps drop to 10C.

BP

Bonnie, I lost them last year because the room I used was too warm. I don't have a cold room or root cellar, but a reasonably cool room will do. I've had success other years by leaving them right in the pot and putting them up against an outside wall in an upstairs bedroom and just leaving them alone all winter. (This is after the foliage has been killed by frost to induce dormancy.) I guess I'll go back to that method this year. I might put a few sheets of newspaper on top to keep the light off, but I haven't done that in past years.

Janet's Garden

I've never tried leaving them in the pot - I always took them out to cure and then stored them in peat. I might do that next time - I do it with a couple of others, but I didn't think to try it with begonias. I didn't buy any this year so I won't get to find out for a bit if it'll work.

I also never left them to have the top killed off - I dug them up before that happened. Another thing to do differently next time :-)

BP

I've overwintered my begonias in different ways. One, last year, I just left in the pot when I brought it cause it was planted with a type of ivy that I wanted to keep going. It sort of died down on its own, and came back fine this summer.
Others, I stored in a paper bag along with my glads, cannas and callas, which then went into a cardboard box on a bookshelf in my dining room. (My dining room does get very cold in the winter.) They did just fine, too. I know you're supposed to store with peat, so they don't dry out, but I checked them several times during the winter, and they were fine. Close to spring, everything started sending out the little eyes, so I started to pot up the begonias, just to give them a head start. The others had to wait till they could go in the garden.