Inside

When I lived in Zone 6, I grew begonia grandis (a.k.a. begonia evansiana) in an outside bed. I started with one original plant from a friend. The next spring I had quite a few plants that sprouted from bulblets; the bulblets had dropped off the mother plant the previous fall. I carefully moved these within the desired location and had a lovely bed of lush foliage in the growing season and beautiful pink flowers in late summer/fall. The plants continued to reappear faithfully each spring. - June

Begonia grandis is the hardiest begonia and the only one that might be hardy in zone 5. It's fully hardy in zone 7 and I believe in zone 6 as well, but in zone 5 may need some protection (mulch and/or planting near a foundation). It's a nice plant, but where it's hardy can be somewhat weedy.