Hello,

I have a mandarin orange tree and a yuzu tree. I'm in Vancouver BC, so I keep them outside on the deck to get as much sun (I don't have any south-facing windows). We're expecting temperatures down to -6 C (21 F) tomorrow evening. I built a little greenhouse to keep them warm over the winter, with christmas lights inside to provide heat. This rises the temperature from outside by about 5.5 C (10 F) degrees when the lights are on.

But at night, I turn the lights off for safety. And I'm concerned that this cold might be just a bit too strong (I lost a meyer lemon tree from a rough winter a couple years ago, although that was not as hardy as these trees supposedly are). So I am thinking of taking the trees indoors for a few nights.

I am concerned that taking them indoors might be a shock to them. And indoors is pretty dry, too. I can mist them a bit to help, if that would actually help. What other steps can I take to not blow their tree minds? Am I overprotecting them?