The life span of a fresh-cut Christmas tree depends on a few factors, such as the species of tree, the climate, and how it is cared for. In general, a freshly cut Christmas tree will last for several weeks if it is properly watered and placed in a cool, humid environment. However, some species, such as the Balsam Fir, are known to last longer than others. With proper care, a fresh-cut Christmas tree can last for up to six weeks or more.