So it's been a few weeks since I got my Darlingtonia, and I've been trying to figure out a way I can keep my plant in the sunlight all day without it getting overheated. I decided I was going to create a system where I would have a separate, insulated reservoir that would house a small water pump, which would (in theory) pump cool water over the roots of the plant all day. The pump would be solar-powered, so it would only come on when needed... In most of California, heat and lack of sunlight are mutually exclusive, so I'm not sure how this system would work out for those of you in the east where nights are warm too.
My supplies were as follows:
Solar-powered water pump - I used this one
8" plastic pot - this is the main reservoir
Decorative glazed clay pot - for insulating the reservoir pot
Tray for a 10" plastic pot - just happened to fit perfectly as a lid for the 8" pot when turned upside-down
A few feet each of 1/4" and 3/8" clear tubing - you can just use the 1/4" if you want
And of course, my Darlingtonia plant
Assembling this contraption was relatively easy. For the main compartment, I filled the clay pot with water (more insulation), then put the plastic pot inside of that and filled that with distilled water. I then cut a hole in the tray (lid) and fed the tubing and wire through. The 1/4" tubing connects to the output on the pump, and at the end of that tube I attached one of the fountain heads that comes with the pump using a small section of the 3/8" tubing. I also tied a knot in the 1/4" tubing because I found the water output was too strong for this purpose. Then one end of the 3/8" tubing goes in the reservoir pot, and the other into the Darlingtonia's outer pot (you need to remove the air from the tube so water can flow freely between the two vessels). As a final touch, I wrapped the tubes in white duct tape to prevent the water from heating up as it flows from one pot to the other.
This system ran perfectly, but I still have concerns about the water temperature. Today was a relatively warm day with air temperatures in the mid-80s, and I found that by 3:00 pm, the water temperature even in the shaded reservoir (and consequently the plant's roots) was approaching 80°F, so I put some cold water in to cool things off a bit. I know that 27°C/81°F is the critical temperature for Darlingtonia, but I have some questions about what exactly that means. Does that mean that the plant cannot tolerate that temperature at all, and if the roots get that warm you might as well throw the plant away because it won't be able to recover? Or is it possible for the plants to endure relatively brief spikes (say, 1-2 hours) of that temperature or slightly above as long as water is constantly flowing over the roots and it cools off at night? When I check the root temperature in the morning, it is usually 52-54°F.
I've been wondering what it is exactly about the warm root temperatures that kills Darlingtonia. Is it just that the plant physically cannot function at that temperature, similar to how humans die if their body temperature reaches about 108°F? Or is it due to external factors, such as root rot or the lack of oxygen in warmer water? If it is the latter, it seems like having water constantly flowing over the roots would remedy that even if the temperatures are above optimal. My plant is of the Sierra Nevada variety, which is supposed to be more tolerant of blazing sunlight, low humidity, and higher temperatures than the coastal types. Would this make a difference in the hardiness of the plant?
I guess I'll have to wait and see how this goes, but in the mean time I have ice cubes ready to pop in the reservoir if necessary.