Costco typically starts to receive Christmas trees in late October or early November, depending on the year. Some of the first shipments may arrive in October, but the main bulk of the trees will arrive closer to the start of the holiday season in November. Costco offers a variety of Christmas trees, including fresh and artificial trees, as well as pre-decorated trees. You can also find a wide selection of ornaments, lights, and other Christmas decorations at Costco.