Tu BiShvat is a Jewish holiday occurring on the 15th day of the Hebrew month of Shevat .The day that marks the beginning of a “new year” for trees. This is the season in which the earliest-blooming trees in Israel emerge from their winter sleep and begin a new fruit-bearing cycle. It is also called "Rosh HaShanah La'Ilanot" (Hebrew: ראש השנה לאילנות), literally "New Year of the Trees." In contemporary Israel, the day is celebrated as an ecological awareness day, and trees are planted in celebration.
On Tu BiShvat 1890, Rabbi Ze'ev Yavetz 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 Kayemet Le’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.
It is a custom to eat fruit on Tu BiShvat, like figs, dates, grapes and also nuts. But why do we eat dried fruits insteas of fresh ones during this holiday? Well, the answer is interesting: in the past the people of Israel were in exile, and it was important for them to eat fruits originating in the Land of Israel. Therefore, because of the trading and conservation conditions of the time, of course, they have failed to bring to all Diaspora Jews fresh fruits from Israel, but "had to" make do with dried fruit. The custom of eating dried fruit remained until today.