The Christmas tree needs water to stay healthy and to continue to provide that Christmas cheer. It's important to keep the soil moist but not too wet. You can check the soil by sticking your finger in it. If it's dry, then it's time to water it. Make sure to use lukewarm water, and avoid pouring it directly on the tree's trunk. Just pour the water on the soil around the base of the tree, and let it soak in.