Trees and their New Year in Rabbinic Judaism
Trees were viewed in both economic and symbolic terms by the Rabbis of Talmudic times.
While Tu Bishvat as we know it today came about long after the days of the Talmud, this day and its central concern--trees--are important in Rabbinic literature.
The Four New Years
Rabbinic Judaism teaches that there are four new years. While there is some debate as to the exact date of each one, the consensus holds the following. The first of the month of Nisan is the new year for kings and festivals; the first of Elul is the new year for the tithing of animals; the first of Tishrei (Rosh Hashanah) is the new year for calendar years, sabbatical years, jubilee years, planting, and vegetables; and the 15th of Shvat (Tu Bishvat) is the new year for trees (Babylonian Talmud Rosh Hashanah 2b).
The primary role of a new year for agricultural items is determining what products are certified for tithing. It thus essentially represents a tax on assets that is paid through sacrifices to God and direct offerings to priests and the poor. In the aftermath of the destruction of the Second Temple, the system of four new years remains as a marker of the central role that Temple worship and tithing played in the relationship between the Jewish people and God. Each new year marks a key component of this relationship.
The New Year for Kings and Festivals represents a yearly affirmation of the social, political, and religious structure of the nation. The Temple, particularly during festivals, was the vehicle for the masses to recognize and support the leaders responsible for the cycle of sacrifices that kept the Jewish people in good stead with God. The kings ruling over the land of Israel had to ensure that this system was functional and protected. Because ancient Israel was primarily an agricultural society, temple tithing as well as other forms of cultic tribute and sacrifice consisted of the vegetables, fruits, and animals that people cultivated.
The new years of the first of Elul and Tishrei and the 15th of Shvat shared the responsibility for marking the process of generating the resources that quite literally fed the cultic system. These new years determined the larger and smaller scale cycles for planting, harvesting, and offering or consuming Israel's most valuable goods.
While the rabbis preserved the first of Tishrei as Rosh Hashanah--celebrated today as the beginning of the Jewish calendar year as well as the start of a period of intensive individual and communal spiritual introspection and repentance culminating in Yom Kippur--the other three new years faded from Jewish practice. Nonetheless, rabbinic tradition continued to develop a rich body of texts and ideas about trees, even as the holiday of Tu Bishvat lay all but dormant for hundreds of years.
Trees in Rabbinic Thought
If the cycle of four new years provides a periodic measure for discerning how the Jewish people as a whole relates to God, trees serve as a symbol and metaphor for the spiritual choices of individuals.