Although the tubers that develop can be left in the ground where winters are milder, for me they have to be treated as an annual since freezing temps of the soil will destroy any tubers left in the ground. Small tubers do develop on the seed grown types which like any other in colder climates will require digging before winter.

Yes, i have to dig them up too. I was just wondering about the seed to tuber thing. Which you answered. Thanks!