Hi Tarev,
I was killing them too but one year, I was down to one "rock" so put it out under the carport and told it to die. No water, no protection, except from rain (Zone 8). To my surprise, in the spring it was alive and well and growing! It's the green one on the right. I suspect if you toss yours outside for the winter in a dry spot, it will thrive. Humid but dry and cool. I decided that must be the formula for success. Now it lives on a back shelf in my greenhouse, the shadiest spot I could find and it gets watered when the "rocks" get soft.
Daisy
