I've debated a ton on how I'm going to overwinter my Juniper Bonsai. Leave it in the pot on the ground, buried in the ground, the garage(I thought this would kill it, but I guess it can be done) and finally use my egress window. I felt the egress window would be best, as it would keep the snow off, let it have natural light and keep the harsh winds. As you can see in the photo's, there is a clear top to the egress window. You can see trees through the lid, the photos don't do it justice. It's not seal tight or anything and you might be able to see a rock holding it down. Problem: I went to the basement to check on the Juniper, it's still just as green as the day I got it. The two apple tree's that my children and I planted together are in there too. I thought it would be a great place for them to overwinter as well, but it appears they still have green leaves. Granted the Juniper is starting to brown a bit on top and the apple trees don't have nearly the amount of leaves they had on them before. Outside is currently 34 degrees F. Not a tree in my area has a leaf on them and my garden looks like tumble weeds. The temperature inside the egress window is warmer than the outside temperature but still cold. Question: Will this egress window create a greenhouse effect and prevent the Juniper from going dormant? Should I wait a little longer? Our winter is only just getting started and will be much colder soon with snow on the way sometime soon. Also, if anyone knows anything about apple trees, would it be ok for them to remain in the egress window if it is creating a greenhouse effect? I really don't want them to die, my children would be bummed. Thanks!