Tu BiShvat is a Jewish holiday occurring on the 15th day of the Hebrew month of Shevat (in 2021, Tu BiShvat begins at sunset on January 27 and ends in the evening of January 28). It is also called Rosh HaShanah La’Ilanot , literally ‘New Year of the Trees’. In contemporary Israel, the day is celebrated as an ecological awareness day, and trees are planted in celebration.

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 Hasidic 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.

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.

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.

In the diaspora, starting especially in North America in the 1980’s, Tu BiShvat became treated as the Jewish “Earth Day” — with contemporary communities emphasizing all kinds of actions and activism related to the environment and the natural world. The modern Tu BiShvat seder, which often combines the Kabbalistic structure of the seder with ecological themes, also has its origins in the United States in the early 1980’s.