Christmas trees are grown in a variety of climates, from mild to cold, and they can be found in both northern and southern hemispheres. In the United States, they are typically grown in the Northeast, Midwest, and Northwest regions, as well as in parts of the South. Many Christmas trees are grown on tree farms, where they are carefully cultivated and pruned for optimal growth and quality. The trees are harvested when they reach a certain height, typically between 6 and 15 feet, and then shipped to markets and stores for sale during the holiday season.