I have a few highlanders which were supposedly tolerant of lowland conditions (think the easiest highlanders), however they are on a steady decline since I put them in my terrarium. Besides investing in heavy cooling machinery, is there an alternative way to cool them? Ice? Someone on this forum mentioned that it is possible to grow N. rajah (not saying that I have it) with ice once, Nepenthesgracilis, if I am not wrong.
Also, I read recently that Highland Nepenthes will stand the heat if their roots are kept cool. This led me to a question: are there particular parts of the plant (ie. roots) which lead the Nepenthes to thinking it is in a highland habitat? Or at least some parts are more important to be kept cool than others? Because providing a root cooling system (something like Darlingtonia?) would be much easier than terraforming a fridge (tried that).
Thank you for your suggestions.