In ancient times this "new year" was connected with a tax levied on fruit trees in Israel. Because of its secular nature, the rabbis treated Tu B'Shvat (literally, the 15th of the Hebrew winter month Shvat), as a very minor holiday. Jewish mystics in the 1600's linked this holiday with the Kabbalistic notion of the "Tree of Life", and began holding seders, or celebratory meals in its honor, using wines of varying colors, fruits and nuts, symbolizing the passage of the seasons.

With the rise of environmental movements Tu B'Shvat has taken on another dimension, and is now considered the "Jewish Earth Day". Our responsibility for the earth has its roots in the Jewish ideas that we are partners in creation, and Jewish environmentalists have developed the concept of "eco-kosher" as a synonym for "environmentally and socially responsible" or "green".