Trachycarpus fortunei Tesan is a variety of windmill palm grown in China from an area where windmill palms are not normally grown. It's said to be very cold hardy to -4f and is sometimes claimed to be the most cold hardy trachycarpus. It is also said to be a very large from in all aspects with a larger trunk having more fiber, with leaves having more blunt tips than typical fortuneis. These are still young and do seem relatively slow and quite hardy so far. I don't have any of these planted out just yet to really test them and customers will be testing them along with me.