A Christmas tree needs water to stay fresh and vibrant during the holiday season. The length of time that a tree can survive without water depends on a variety of factors, such as the type of tree, the amount of water the tree was given before being cut, and the climate where the tree is located. Typically, a Christmas tree can last anywhere from a few days to a few weeks without water. To ensure your tree lasts as long as possible, be sure to give it plenty of water and keep it away from heat sources.