I am planning to build a highland terrarium for few of my plants (south american Drosera, Nepenthes, Helimphora, Utricularia, etc). Before buying anything, I would like to know few things:
I am tempted to grow highland Nepenthes, but I need to know how 'strong' the cooling must be in order to planify my terrarium setup (if it need to be cooled at night or not). I am thinking to build a brand new styrofoam terrarium (as seen on the french CP forum: great for insulation, light and cheap to build) cooled with an old freezer element (+thermostat), but since I have 2 old 20 G aquarium here, why not try to simplify all this(work and money!)?.
Being in Canada, night cooling can be achieve 'easily' but putting it near a window and bringing in cool air (well, that what I think, and seems to work for Swords!). But during summer, it can be a major problem (especially from next automn, since I will be moving to a 4th floor appartment)! It is sure that i can cool it with frozen bottle during the hottest months of summer, but in the case it is not sufficient during this period, can highland Nepenthes hold a bit warmer temps for a relatively short period (2-3 weeks?) during night? If yes, which one?
What is the 'superior limit' of temperature most highland can hold (for those few weeks)?
All the reading about cooling a terrarium is getting me back on Nepenthes track, genus I almost took away from my collection 5 years ago... With a little luck, I'll be able to provide cool enough temps to begin to think about getting a Nepenthes hamata
Any infos are welcome!
My Nepenthes regularly saw high temperatures of 27C (80F) when I had them indoors. Now that they are outside, they _occasionally_ see highs of 30 or 31C (86-88F), which from what I understand is too hot, but they seem fine so far. In fact, the only time there was any damage, was when I took the lid off because I thought it was too hot. I had to leave it off for a couple of hours while I went to school, and the next day one of my highland plants had a lot of blackspots from the prolonged humidity drop. Amusingly, this is one of my slowest growing plants, but it had no problem turning black and showing its unhappiness.
As to how much cooling is necessary I'm not sure. I always strive for 5-10C (41F-50F) at night. When I had my plants with only night time drops to 15-20C (60-68F), they didn't seem to grow as well. Smaller pitchers with less color, and slower growth.
How much warmer would your two-three week period be? I bet it would be fine. My highland plants survived about 6 months with only night time "drops" to 20-22C (68-71F). A lot of them didn't pitcher, but the more resilient ones did (most notably spectabilis and tentaculata), and none of them died.
That's the thing I wanted to hear
Originally Posted by [b