Do evergreen trees lose their leaves in the winter?

yes No, but I will explain. All green things have a growing season. That's why the corn in the field dies and the oak trees' leaves fall off. The usual ideas about cold weather or shorter days are bogus. You can fool plants into lengthening their growing season, but not by much! So just the same as evergreens know when to shoot out new growth and when to drop pine cones, they shed needles too. And I hope you didn't mean Christmas trees......