Tu Bishvat is the New Year of the Trees. What is the source of this holiday?
Tu Bishvat is mentioned in the Mishnah in a section listing the special times in the year which signify the start of a new year.
בְּאֶחָד בִּשְׁבָט, רֹאשׁ הַשָּׁנָה לָאִילָן, כְּדִבְרֵי בֵית שַׁמַּאי. בֵּית הִלֵּל אוֹמְרִים, בַּחֲמִשָּׁה עָשָׂר בּוֹ:
On the first of Shevat is the New Year for the tree in accordance with the statement of Beit Shammai. Beit Hillel say: on the fifteenth of Shevat.
The Mishnah states that for the purpose of deciding the age of a tree, the new year starts on either the first or fifteenth day of the Hebrew month of Shevat. Missing from the Mishnah is any description of the Tu Bishvat holiday that is celebrated today.
Mishnat Eretz Yisrael is a 21st-century commentary on the Mishnah that combines traditional and academic methods of interpretation, with an emphasis on the Land of Israel as the backdrop of the Mishnah’s development. Written by professors Shmuel Safrai z”l, Chana Safrai z”l, and Ze’ev Safrai, the commentary is enriched by the authors’ knowledge of history, geography, archaeology, and more.
The Mishnat Eretz Yisrael commentary begins with a general statement about the 15th of Shevat (Tu Bishvat) as described in the Mishnah.
יום חמישה עשר בשבט לא היה מוכר כיום מועד משמעותי, והופעתו ברשימת ראשי השנים שבמשנה אינה מעידה על מעמדו החגיגי או המיוחד בלוח השנה היהודי. הוא מופיע במשנה רק כיום טכני לקביעת מעשרות.
The fifteenth day of Shevat was not known as a day of any festive significance; and its appearance on the list of new years in the mishnah does not indicate its festive or special status on the Jewish calendar. It only appears in the mishnah as a technical date for the demarcation of tithes.
Through analysis of both Talmuds (Babylonian and Jerusalem) and other sources including archaeological discoveries, the commentary paints a picture of life in Israel and Babylonia and points out differences between the two communities. Here’s what they have to say about Tu Bishvat.
ניתן, אפוא, לסכם שבארץ ישראל לא ציינו את ט"ו בשבט כלל, ובבבל הייתה לו משמעות מעטה.
It can then be concluded that they did not commemorate Tu Bishvat in the Land of Israel at all, and that it only had minor significance in Babylonia.
Finally, Mishnat Eretz Yisrael discusses the development of Tu Bishvat and how it is celebrated today.
העדות הקדומה ביותר לציון ט"ו בשבט כיום מועד היא תשובה של רבנו גרשום מאור הגולה המזכיר כבר את היום כיום האסור בתענית. אך את עיקר משמעותו קיבל היום עם פריחת הקבלה. המקובלים הפכוהו ליום חג, כחלק מחידוש קשריהם וזיקתם לארץ ישראל הרוחנית והממשית. מאז מצוין יום המועד ברחבי ישראל, בתודעת הציבור התקשר החג לארץ ישראל והפך לביטוי לגעגועים לארץ ולזיקה אליה.
The oldest indication of Tu Bishvat’s designation as a festive day is a responsum of Rabbenu Gershom, light of the exile, who already mentions the day as one on which it is forbidden to fast. However its main importance today came about with the blossoming of the Kabbalah. As part of the renewal of their ties and attachment to the spiritual and actual Land of Israel, the Kabbalists turned it into a holiday. From then on, this festive day is observed throughout Israel. In the communal consciousness, the holiday has become connected with the Land of Israel - as an expression of the longing for, and of the attachment to, the Land of Israel.
Read the entire commentary on the Tu Bishvat section of the mishnah in Hebrew or English. The rest of Mishnat Eretz Yisrael can be read in Hebrew on Sefaria.