Unfortunately, it's not recommended to hose down an artificial Christmas tree. Artificial trees are usually made from plastic, which could be damaged by water or create electrical hazards. If you need to clean your artificial tree, you can use a soft brush or vacuum cleaner with a brush attachment to remove any dust or debris. Additionally, you can use a damp cloth to spot clean any stains or spots on the tree. Remember to always read the care instructions provided by the manufacturer before cleaning your artificial tree.