By: Rabbi Ari Enkin
Tu Bishvat is, of course, the New Year for trees and it is said that from this day onwards the upcoming season’s fruits have begun to take root. It is customary to partake lavishly in as many different fruits as possible on Tu Bishvat. Some Chassidim, including many Rebbes, wear their distinctive Shabbat garb on Tu Bishvat in honor of the day. Many sifrei minhagim make mention of an ancient custom to recite the daily prayers of Tu Bishvat in the Yom Tov tune. So too, the communities of Syria had the custom to read the Ten Commandments in Arabic on Tu Bishvat.
The halachic significance of Tu Bishvat applies primarily to the mitzvot of teruma, maaser, and other agricultural mitzvot, most of which are only binding in Eretz Yisrael. One should not recite the birkat ilanot until the month of Nissan even if one happens to see fruit trees beginning to blossom from Tu Bishvat onwards. It is taught that one should try to give tzedaka in multiples of ninety-one on Tu Bishvat – the numerical value of “ilan”, tree.
It is said in the name of Rav Chaim Vital that one should endeavor to eat thirty different types of fruit on Tu Bishvat: ten fruits which are eaten in their entirety, ten fruits of which only the interior of the fruit is eaten, and ten fruits in which only the exterior is eaten. Other kabbalists teach that only fifteen different fruits are necessary. As Tu Bishvat is specifically the New Year for trees, there is no particular significance in eating fruits that grow from the ground. Some sources indicate that the custom of eating fruits on Tu Bishvat applies specifically to the night of Tu Bishvat though most others insist that the entire twenty four hour period is equally appropriate for eating fruits.
It is appropriate to eat an etrog on Tu Bishvat, especially the etrog that one used on Sukkot, if possible. In fact, one should use the day to pray that one be allotted a beautiful Etrog for the upcoming Sukkot. Indeed, even in years when Tu Bishvat falls out on Shabbat, one is permitted to pray for a beautiful etrog for Sukkot – even though personal supplications are generally forbidden on Shabbat. Some have the custom to hold an elaborate ceremony known as the “Tu Bishvat Seder” complete with four cups of wine, mystical readings, and other prayers.
One should take the opportunity afforded by Tu Bishvat to reflect and thank God for the fruits that He has created for our enjoyment. The holiness to be found within fruit all over the world emanates from the fruit of Eretz Yisrael. Furthermore, one who eats fruits of Eretz Yisrael imbues his soul with holiness. It is the custom of some Chassidim to bless each other with “May you merit good fruits” enigmatically referring to children. Many people mistakenly attribute Tu Bishvat as being the day of judgment for trees. However, trees are judged on Shavuot, not on Tu Bishvat.
There is a custom to begin a daily study of Masechet Megilla on Tu Bishvat, which would allow one to make a siyum on Purim. Indeed, one may combine the Purim feast and the siyum celebration in one meal without concern for the prohibition against combining mitzvot and different celebrations (“ein osin mitzvot chavilot”). Although Tachanun is not recited on Tu Bishvat this custom is likely only of recent vintage. There are those who rule that Tachanun should be said at the mincha before Tu Bishvat  while others who rule that it should be omitted.