Begonia grandis is a beautiful begonia either as an individual plant or in the landscape and is probably the oldest begonia know to us having been immortalized from antiquity Chinese Art. It is also one hardy in the ground to New York. To see it at its best in the landscape go to this website:
http://dctropics.blogspot.com/...
I'll post another comment about begonias from seed since I can only figure out how to post one website per comment.