The lifespan of a Christmas tree depends on various factors such as the type of tree, the care it receives, and how it's used. On average, a real Christmas tree will last anywhere from 3 to 6 weeks before it starts to dry out and shed needles. If the tree is properly cared for with regular watering and maintenance, it may last slightly longer. Artificial Christmas trees can last much longer, often lasting for several years if stored properly and taken care of.