Yea may be milder down here, but I left them in the ground covered with straw for two years, then dug them up put them in a big bucket of peat the next year because didn't want to grow them in the same place and they started to shoot in the shed so planted them out they were fine. From seed you get one or two shoots but from the tubers you get four or five really strong shoots. That was three varieties Tenderstar, Firestorm and Moonlight I change to new seed this year Armstrong supposed fantastic taste well the jury is still out on that one didn't think was that much better.
Cheers Arry