Tu B’Shevat, or the “New Year of the Trees,” is Jewish Arbor Day. The holiday is observed on the 15th (tu) of the Hebrew month of Shevat. Scholars believe that originally the holiday was an agricultural festival, marking the emergence of spring. In the 17th century, Kabbalists created a ritual that is similar to a Passover Seder, which many Jews still hold a modern version of today. The holiday also has become a tree–planting festival in Israel, in which Israelis and Jews around the world plant trees in honor or in memory of loved ones and friends.