Before the destruction of the Second Temple in Jerusalem in 70 CE, 10 percent of all produce was set aside for the support of the priestly class and the poor, and the Jewish festival of Tu B’Shevat—which means “the 15th of the month of Shevat”—marked the beginning of a new fiscal year for tithing. According to Jewish law, fruit may not be eaten during the first three years of a tree’s life; the fourth year’s fruit is for God, and after that, the fruit can be eaten. The fifteenth of the Jewish month of Shevat was the cutoff date for determining when the fruit of the tree was to be tithed. If the tree was planted prior to Tu B’Shevat, it would be considered to have aged one year. If it was planted afterward, its age would change during the next year’s Tu B’Shevat. Thus, Tu (for tet-vav, from the alpha-numerical expression of the number 15) B’Shevat became the festival of the trees, or literally the “new year” of the trees.
In the 1600s, Jewish mystics in Israel instituted a special Tu B’Shevat meal or seder, sometimes called chemdat hayamim, “meal made from the fruits of the season.” During this meal, participants eat four different categories of fruit—especially those honoured in the Torah, i.e. grapes, figs, pomegranates, olives and dates—and drink four different combinations of red and white wine or grape juice, symbolising the four seasons. It was the early pioneers of the State of Israel that began planting trees on Tu B’Shevat, a practice which is nowadays also observed outside of Israel.