Real Christmas trees can last anywhere from a few weeks to a few months, depending on the tree and how it's taken care of. If you water it regularly and keep it in a cool, dry place, it can last up to two months. But if you neglect it or place it in a warm, humid room, it may start to lose its needles and dry out in a week or two. So it's important to pay attention to the tree and take good care of it if you want it to last through the holiday season.