StrUktO wrote:what do you do to shelter them if needed?
I use transparent PVC on a wooden frame as rain protection, from begin October to mid March. Very important is also a good drainage.
More info are here
StrUktO wrote:and where in germany do you live?
Look at the map
Opuntia fragilis "Freiberg"
Charles wrote:You and I have a lot in common. I grow hardy cactus in Reno, NV USA. What grows here grows in Germany, I think.
It's probably possible but the winter in NV is much more dryer than in Germany. I'd think the low temperatures are not the problem. The to high humidity is more dangerous for the plants. It rises to over 90% for many weeks. The plants could get mold.