The best time to buy a fake Christmas tree is usually around the end of October to early November, as that is when retailers will start putting them on sale for the holiday season. However, it is always a good idea to keep an eye on sales throughout the year, as you may be able to find a good deal at any time. Additionally, if you want to avoid the crowds and hassle of shopping during the holiday season, you may want to purchase your tree earlier rather than later.