A Christmas tree should be watered regularly to keep it healthy and looking fresh. Depending on the size of the tree, it should be watered every few days or once a week. Make sure to check the soil regularly, and if it feels dry, it's time to water your tree. When you water your tree, use room-temperature water and allow it to drain fully before putting the tree back in its stand. Remember, a well-watered tree will last longer and stay healthier throughout the holiday season.