Ancient Persians also decorated an evergreen tree called SARVE. The SARVE or "Rocket Juniper" - also known as the cypress tree, being straight, upright and resistant to the cold weather, was known as a symbol of enduring hardship, thus appropriate for celebrating Mithra. The younger ones had their "wishes" symbolically wrapped in colorful silk cloth and hung them on the tree along with lots of offerings for Mithra in the hopes that he would answer their prayers.
Again in the same tradition, Luther, the famous German reformer, in mid 18th century (1756), having learned of the YALDAA SARVE, introduced the Christmas tree to the Germans. As cypress trees were not widespread in Germany, as indeed in most of Europe, the chosen tree became a variety of pine which was abundant in Europe.
Zarathustra: Good Thoughts, Good Words and Good Deeds