This article first appeared at http://judaism.bellaonline.com

Tu Bishvat, the fifteenth of the month of Shvat, is known as the New Year for the Trees. Tu Bishvat is called such because each Hebrew letter has a numerical equivalent—the term Tu in Hebrew is spelled tet vav—tet is equal to nine and vav to six, equaling fifteen.

Although this was originally a legal designation, Tu Bishvat has, in recent years, become increasingly significant for Jews across the observance spectrum and is particularly so for those with a keen interest in ecology and environmentalism.

Tu Bishvat is mentioned in Tractate Rosh Hashanah as being one of the four new years on the Jewish calendar. The Jewish calendar is unique in that it is both a lunar and a solar calendar. While the months are determined according to the lunar cycle, we make adjustments to the calendar so as to align with the solar, chiefly so that the holidays are observed in the proper season. The other new years on the Jewish calendar are Rosh Hashanah, which falls on the 1st and 2nd of Tishrei and is undoubtedly the most well-known, the 1st of Elul which is the new year for animal tithes, and the 1st of Nisan which is the beginning of the year in terms of festivals and is also the beginning of the year for kings.

There was a dispute in the Mishnah between the schools of Hillel and Shamai as to whether the new year for the trees should be observed on the 1st of Shvat (Beit Shamai’s position) or on the 15th (Beit Hillel’s position). As with the majority of Halakhic (Jewish legal) matters, we follow the opinion of Beit Hillel.

Tu Bishvat was initially significant owing to the laws of tithing found in Leviticus 19:23-25. Orla, which is still observed today, is the prohibition of eating fruits from a tree during the first three years after it has been planted. In the fourth year, we are to take first fruits to G-d in Jerusalem, also known as Nedah Rev’ii. From the fifth year onwards the fruits may be consumed. Thus, Tu Bishvat marks the date upon which years are counted for this purpose. In theory, if you planted a tree on the 1st of Shvat, Tu Bishvat would mark the end of the first year and the beginning of the second.

The Kabbalists in Safed imbued Tu Bishvat with a great deal of mystical significance. In the seventeenth century, a Tu Bishvat Seder, modeled after the Pesach Seder, was created by Rabbi Isaac Luria and his disciples. Holding a Tu Bishvat Seder is widely practiced by Jews today regardless of affiliation and may take a number of forms.

The Tu Bishvat Seder as envisioned by the Kabbalists using as its primary text a Kabbalistic work called Pri Etz Hadar—literally Fruit of the Beautiful Tree–which was heavily based on the Zohar, which is traditionally attributed to Shimon Bar Yochai who lived in the 2nd century of the Common Era, but which scholars believe was written by Moses DeLeon in the 13th century in Spain. The Zohar is the most important Kabbalistic work. The Tu Bishvat Seder in the Kabbalistic tradition was very much focused upon the Tree of Life, the Kabbalistic map of the sefirot, or ten emanations of G-d, as it were.

The overarching focus of the Seder related directly to Rabbi Isaac Luria’s teachings concerning divine vessels, or klipot, and the importance of restoring the world to a sense of wholeness or completion. There is a customary order in which a person is to eat fruits during a Kabbalistic Tu Bishvat Seder, going from the outermost reaches of reality to the inner, symbolized by the physical appearance and attributes of the fruits themselves. You begin by eating fruits and/or nuts with hard, inedible exteriors and soft interiors, such as bananas and walnuts, then moving next to eating fruits and/or nuts with soft, edible exteriors but with inedible pits such as dates, olives or apricots, and finally ending by eating fruits which can be eaten whole, such as figs. The combination of red and white wine or grape juice that is also consumed along with the fruit holds mystical significance as well.

Contemporary Tu Bishvat sederim need not hold strictly to this model, but might incorporate bits and pieces of it, or may choose instead to focus on an urgent issue of ecological concern. They might also incorporate classical or contemporary Jewish texts which speak directly to Jewish attitudes concerning the environment and our duty to protect it and the bounty we receive from it.

Although holding a Tu Bishvat Seder is a very meaningful experience, it is not necessary to observe Tu Bishvat. Other common ways of observing Tu Bishvat are consuming a new fruit, consuming one or all of the Shivat HaMinim (seven species of the Land of Israel) which, according to Deuteronomy 8-8 include dates, figs, olives, wheat, barley, grapes and pomegranates. Many people, particularly in Israel, plant trees on Tu Bishvat and the Jewish National Fund plants significant numbers of trees each Tu Bishvat.

Tu Bishvat is also a time when we can reflect upon important environmental issues and concerns. It is an opportunity to delve into what the thousands of years of Jewish tradition and teaching has to say on our obligations towards the environment and how we are to care for and observe it. If we are so moved it is also a time to take personal action on environmental issues that are personally meaningful to us and to our communities.