In my gardening lifetime, I've come to the conclusion that begonias are the hardiest of plants. One even a brown thumb couldn't kill ... though not impossible. Given the right requirements or even a little bit of their requirements. This angel wing (I suppose that's what it's called) was/is literally the first plant ever given to me. About eight years ago.
I used to keep it on the kitchen counter under artificial lighting not suitable for plants. I think it was the good vibes I gave it that kept it going. I loved it so much my husband would get jealous and threaten to pee in it.
It froze this year in the green house but it missed me and came back.
