Air potato (Dioscorea bulbifera) and Chinese yam/Light root (Dioscorea batatas) are relatives.
The former grows big aerial tubers/bulbils, the later is cold hardy.
Is it possible to somehow graft the air potato stem onto the Chinese yam roots and grow aerial tubers in a colder climate (7a)?
What I don't understand is how they changed the earth's orbit to fit the metric calendar. Tiny ad:
Permaculture Adventure Bundle - 43 digital goods for freaky cheap!