I am wondering the same thing. Brought in my Elatior and it is in a cool room, afternoon sun, and I see that some stems are kind of rotting at the base and falling off although it is still blooming nicely. Never have had any luck starting them from cuttings or wintering them. THis is a new variety so thought I would try again. Any suggestions as to temp. and should they be on the dry side or kept moist.

Only tuberous begonias go dormant. Cane-like, shrub-like, thick-stemmed, rhizomatous, trailing/scandent, semperflorens and rex begonias do not. They don't grow much in the winter, but they don't go dormant.