My wax begonias winter well. They go dormant. I lose some in summer heat or drowned in winter rain but a fair amount come back each year. In a pot I have a glorious white one with the dark leaves that is big and round. Since it is the second year and in a spot it likes, it popped up BIG.

They are reliable perennials here too. In a pot, sunny windowsill, it will bloom all winter, have one that's been blooming for well over a year. It would have never occurred to me to bring it inside but it was a Mother's Day present from my son and since I still have a hard time believing these are perennials here (I'm from OH) I felt compelled to "overwinter" it. It's in the ground now, I'll pot a little branch this fall just to be sure... old habits die hard.

I had an entire bed of tuberous begonias winter over here during the El Nino extremely mild winter of 1997-1998, about 40 plants. Blew my mind. We had virtually no snow that year, and apparently the bulbs were sheltered enough that they never froze and died. I bet that won't happen again in a thousand years.

The irony, I wanted to dig them in the fall but just never got around to it. I guess someone was looking out for me.

I lived in northern NJ zone 6 for a while a number of years ago. We had a very mild winter and some wax begonias survived in an area that I had covered with mulched oak leaves. They only survived that one mild winter, we never really had a time where the temp dropped below the mid to upper 20s that winter and maybe one mild snow fall. So, it's possible if the winter is mild and the roots were protected with a mulch of some kind.

My Mom planted this patch of wax Begonias in her yard years ago.