In Eastern Europe, from where Rav Zevin originated, once you dismantled the sukkah the day after Simchat Torah, winter invariably set in. First there was rain and endless mud, and shortly thereafter snow and continuous frost.

The first break after Cheshvan, Kislev, Tevet and half of Shevat — three-and-a-half bitterly cold months — occurred on the fifteenth of Shevat, or simply Chamishah Asar (“fifteen”), as the day was affectionately called. On that day the strength of winter was broken — if not in fact, then at least in theory.

It was Rosh HaShanah, a New Year for Trees, and the hope for the coming spring. Now there were only four more weeks to Purim, and eight or so to Pesach. Indeed, a day to look forward to through the long, bleak winter.

Furthermore, it was the only day in the year when most Jewish families indulged themselves in the unheard-of luxury of eating as many kinds of fruit as were available, and especially fruits that came from Eretz Yisrael. And what vision of “a land flowing with milk and honey” did the taste of figs, dates and pomegranates conjure up in the Old Country … Veritably a special day in that king of a month, Shevat!

Magen Avraham mentions a special custom of Tu Bishvat: “The Ashkenazi communities have a custom of eating many kinds of fruit.” But I do not know why he attributes this custom especially to the Ashkenazi communities. It seems that the Sephardi communities are even more elaborate in their observance of this custom:

“On Tu Bishvat the Sephardi Jews learn in their yeshivot nearly all night long. They enhance the celebration of the festival by eating every type of fruit that is to be obtained the city. Before and after the eating of each kind of fruit they study special passages gathered from Scripture and Zohar; they also pray and sing special prayers and songs.”

There is a special book for this celebration: “The book Pri Etz Hadar (“The Fruit of a Tree of Beauty”), containing the order of prayer for Tu Bishvat, according to the custom of many who fear God and regard His Name.” This is a collection of all the places in Scripture, Mishnah, Talmud and Zohar which speak of fruits, the produce of the land, and trees.

Excerpted from The Festivals in Halachah by Rabbi Shlomo Yosef Zevin, ArtScroll/Mesorah Publications.