I've had a lot of problems getting sarrs to overwinter (I have yet to succeed) outside and for some reason I keep forgetting that darlingtonias need dormancy too. So how tolerant of cold are they? The temp here usually floats around in the teens here. I rarely ever see it get below 10 degrees, my sarrs always freeze and the rhiozome is mush in the spring. It sucks..
Darlingtonia is very cold hardy and has been known to survive well below those temperatures. Heat in summer is more often a problem than cold in winter.
Sarracenia are also hardier than many people think and will survive temperatures in the teens at least for brief periods, but they will not enjoy being frozen solid for weeks on end. The real killer are desiccating winds. A drying wind and frozen pots kills as plants are unable to take up sufficient water.
I think a mixture of that is that is what took out my sarrs. My house is on a hill so it's pretty much always a little breezy here. The winter is just all that much worse. It makes it FEEL like it's in the single digits. I think I've taken care of the freezing issue, I have a bog bowl that probably won't completely freeze and I am planning to put a cold frame on it for extra protection for the VFTs also in it.
It may help that the plants are in a tub that are buried in the soil - that gives them some extra protection from the cold.
Yes, I agree. I also keep the plants in an area somewhat protected from the wind, and in a sunny location so they get winter sun, so they have a chance to thaw somewhat during the day during cold snaps. Make sure to keep them in a large pot to prevent them drying out.