I can keep a Christmas tree alive for up to six months, depending on how well it's cared for. If the tree is placed in a cool, moist environment and regularly watered, it can last much longer than that. However, if the tree is neglected or placed in a hot, dry environment, it will quickly begin to lose its needles and die. It's important to provide the proper care for your Christmas tree to ensure it stays vibrant and healthy throughout the holiday season.