The Windmill palm, Trachycarpus fortunei, tree has been extrensively planted and grown during the last five years in most Northern States and in Canada, much to the incredulous surprise of environmentalists and climatologists. Tropical palm trees are not generally believed to have cold hardy characteristics sufficient to survive in non-tropical locations where temperatures often plunge to depths below zero. The windmill palm, Trachycarpus fortunei, can survive cold weather because of two characteristics: slow growth and a brown-black burlap-like hair that insulates the trunk from winter ravages.
The windmill palm tree, Trachycarpus fortunei, has been reported to grow 20 feet tall in the United States, but the windmill palm is not a native tree here and has only a short history of growing in the United States, after it was imported into Florida from Europe. Many windmill palm trees in Europe are growing as tall as 40 feet. In optimum conditions, the windmill palm tree can grow one foot per year, and the trunk is tall and slender—one foot maximum in diameter—and the base is smaller in diameter than the top, as is the case with many other palm tree species. The width of the windmill palm tree canopy is about 15 feet and the leaves are fan shaped and can grow 3 feet long.
The brown-black burlap-like hair that covers the trunk of the windmill palm is dense and so thick and interconnected that the merristematic growing point in the center of the windmill palm tree is insulated from the cold. After several years of aging, the brown-black hair covering the windmill palm trunk turns grey in color. In Europe, a tourist can find very old, tall windmill palm trees where the hair covering the trunk has eroded, exposing a grey, slick bark trunk with a regal appearance. The fan-shaped leaves are covered with a thick green waxy coat on the surface and the leaf margins are lined with sharp teeth.