Sylvain, they don't like frost periods, few nights with little frost should be possible when the tubers are covered with soil and as long the day temperatueres are above zero. I keep them dry without a drop of water between end of September/early October when the leafs die by colder night temperatures until April when the flowers have died. Tubers which produce flowers like these are between 8 and 12 cm in diameter...baby tubers 1cm in diameter. The hight of the leafes is similar to the hight of the flowers so between 80 and 120 cm. They propagate like weed, so if you want to give it a try and are interested in few tubers, send me a PM with your address and I will send you some tubers.