That's a great question! Fresh Christmas trees can last anywhere from a few days to a few weeks, depending on how they are cared for and the climate they are in. The key to keeping a fresh tree alive and healthy is to make sure it has enough water and to keep it away from heat sources. If you're not sure how long your tree will last, it's a good idea to do some research on the type of tree you have and how to care for it properly.