Tonight we celebrate Tu B’Shvat. There is no Tach’nun by Shachris in the morning according to the Shulchan Aruch, and it is a common minhag in Klal Yisroel to eat different kinds of fruit. The Ateres Tzvi would have many people by his tish and give out lots of new fruit for everyone to make a shehecheyanu on them. It’s brought that the Yismach Moshe of Ujhel zy’a would eat 13 varieties of fruit, presumably in order to arouse the 13 Middos HaRachamim (Traits of Mercy). There are some who say the trees are judged today, but this is essentially incorrect as the gemoro in Rosh HaShonoh says that Shavuos is the Yom HaDin (Day of Judgement) for trees.
To understand how Tu B’Shvat became anything beyond reckoning Orlah and Maaser is practically impossible, it is effectively a folk holiday like Lag B’Omer. To describe something as such is not to be understood as a bad thing or an insult, chas v’sholom, quite the opposite. This shows the great flexibility of Jewish life to fit in more simcha at every turn.
It is commonly done throughout Torah Sh’Baal’Peh and Sifrei Chassidus to compare people to trees, and our state of existence as a field, like in Elul with the imagery of Melech BaSodeh (The King is in the field). Trees also have important symbolic import to us as separate from people, like the Etz Chaim (Tree of Life), serving to show us the flow of Hashem’s influences and the whole pattern of Creation. Even then, the Sefiros on the Etz Chaim diagram are often correlated to parts of the human body.
The essential purpose of eating fruit then on this day is not plain just to eat fruit and make a few extra brochos. We should keep the minhag to eat fruit so as to instill in our minds and souls the idea that our actions should bear fruit, rather than being empty and worthless. Not only that, but our actions should serve to improve the lives of others and make them sweeter, rather than simply bringing ourselves temporary gratification.