Tu BiShvat (Hebrew: טו בשבט) is a Jewish holiday occurring on the 15th day of the Hebrew month of Shevat. It is also called “Rosh HaShanah La’Ilanot” (Hebrew: ראש השנה לאילנות), literally “New Year of the Trees.” In contemporary Israel, the day is celebrated as an ecological awareness day, and trees are planted in celebration.
The name Tu BiShvat is derived from the Hebrew date of the holiday, which occurs on the fifteenth day of Shevat. “Tu” stands for the Hebrew letters Tet and Vav, which together have the numerical value of 9 and 6, adding up to 15. Tu BiShvat is a relatively recent name; the date was originally called “Ḥamisha Asar BiShvat” (חמשה-עשר בשבט), which also means “Fifteenth of Shevat”.
Tu BiShvat appears in the Mishnah in Tractate Rosh Hashanah as one of the four new years in the Jewish calendar. The discussion of when the New Year occurs was a source of debate among the rabbis: “And there are four new year dates: – The first of Nisan – new year for kings and festivals – The first of Elul – new year for animal tithes. Rabbi Elazar and Rabbi Shimon say: – The first of Tishrei- new year for calculation of the calendar, sabbatical years and jubilees, for planting and sowing – The first of Shevat, according to the school of Shamai; The school of Hillel says: the fifteenth of Shevat” (Rosh Hashana:2a)
The rabbis of the Talmud ruled in favor of Hillel on this issue. Thus the 15th of Shevat became the date for calculating the beginning of the agricultural cycle for the purpose of biblical tithes.
In the Middle Ages, Tu BiShvat was celebrated with a feast of fruits in keeping with the Mishnaic description of the holiday as a “New Year.” In the 16th century, the kabbalist Rabbi Yitzchak Luria of Safed and his disciples instituted a Tu BiShvat seder in which the fruits and trees of the Land of Israel were given symbolic meaning. The main idea was that eating ten specific fruits and drinking four cups of wine in a specific order while reciting the appropriate blessings would bring human beings, and the world, closer to spiritual perfection.
In Israel, the kabbalistic Tu BiShvat seder has been revived, and is now celebrated by many Jews, religious and secular. Special haggadot have been written for this purpose.
In the Chassidic community, some Jews pickle or candy the etrog (citron) from Sukkot and eat it on Tu BiShvat. Some pray that they will be worthy of a beautiful etrog on the following Sukkot.
On Tu BiShvat 1890, Rabbi Ze’ev Yavetz, one of the founders of the Mizrachi movement, took his students to plant trees in the agricultural colony of Zichron Yaakov. This custom was adopted in 1908 by the Jewish Teachers Union and later by the Jewish National Fund (Keren HaKayemet L’Israel), established in 1901 to oversee land reclamation and afforestation of the Land of Israel. In the early 20th century, the Jewish National Fund devoted the day to planting eucalyptus trees to stop the plague of malaria in the Hula Valley; today the Fund schedules major tree-planting events in large forests every Tu BiShvat. Over a million Israelis take part in the Jewish National Fund’s Tu BiShvat tree-planting activities.
In keeping with the idea of Tu BiShvat marking the revival of nature, many of Israel’s major institutions have chosen this day for their inauguration. The cornerstone-laying of the Hebrew University of Jerusalem took place on Tu BiShvat 1918; the Technion in Haifa, on Tu BiShvat 1925; and the Knesset, on Tu BiShvat 1949.
Tu BiShvat is the Israeli Arbor Day, and it is often referred to by that name in international media. Ecological organizations in Israel and the diaspora have adopted the holiday to further environmental-awareness programs. On Israeli kibbutzim, Tu BiShvat is celebrated as an agricultural holiday.