The lifespan of a Christmas tree depends on several factors, including the type of tree, how it was cared for, and the environmental conditions it was exposed to. Generally, a Christmas tree will last anywhere from one to four weeks, depending on how well it was cared for. It's important to properly water and nourish the tree, as well as to keep it away from heat sources like fireplaces or heaters, which can dry out the tree and shorten its lifespan. Additionally, keeping the tree away from direct sunlight and keeping it in a cool room can also help prolong its life.