Most of winter, yes, I bury them under a thick layer of wood mulch and coconut coir. I started bringing them back out a few weeks ago, any trees showing signs of budding or leafing out. That means to me the worst of winter is over, and it's warm enough for them to grow again.

The snow in the photo had melted within a few hours. We had large snowflakes, but most of it was not sticking to the ground, and melted quickly.