This what I know, not what I have done, I investigated quite a lot before I decided not to plant the seeds I bought, I should have looked first LOL
Vine, very prolific ..50 feet,with lovely flowers, this often grows well but no tubers underneath
Remove flowers, encourages tubers to grow larger, can grow huge but expect turnip size
Plant very early in the spring
Perrennial in frost free areas.
Lift tubers before frost hits
MUST have long growing season
Grows well in Mexico, Florida but rarely well above that
It is sensitive to the length of the days(can't explain this better) it is grows bigger tubers in short days, which have to be hot, in long days even if hot tubers don't form.
We rarely get short days that are warm.
Needs full sun/partial shade
Can be eaten rare or cooked
Makes a lovely plant.
I left to grow perennial can grow tubers of 50 lbs after several years
I came to the conclusion that there was not much hope here.
Good luck though
XX Jeannine