" When you enter the land and plant any kind of fruit tree, regard its fruit as forbidden. For three years you are to consider it forbidden; it must not be eaten. In the fourth year all its fruit will be holy, an offering of praise to the LORD. But in the fifth year you may eat its fruit. In this way your harvest will be increased. I am the LORD your God.” Leviticus 19:23-25
Jewish people have several New Years. The most well-known are Rosh Hashanah, the Jewish New Year, and our calendar New Year, the one that recently took us into 2010. On the evening of January 29, 2010 we begin observing the New Year of the Trees, known as Tu B’Shevat. Translated, it means the 15th of the Jewish month Shevat. The holiday appropriately coincides with the beginning of Israel's rainy season in Israel.
Why do we have a special birthday for fruit trees? It originates in the Jewish prohibition against eating fruit from trees during the first four years of a tree’s life (see the portion from Leviticus above). After that, there were laws regarding a seven year agricultural cycle. There were various tithes to be separated from produce grown in the Holy Land. These tithes differed from year to year within the seven-year Shemittah cycle, going as an offering to the Temple or as charity to the poor. In order to follow these laws, it was important to know the “age” of a tree. Tu B’Shevat serves this purpose.
Simply, each tree has it’s birthday on Tu B’Shevat of each year. If you plant a tree on the 14th of Shevat, it has it’s second birthday the following day. But if you plant a tree on the 16th, it’s second birthday doesn’t come until the following Tu B’Shevat.
Interestingly, the orthodox tradition of Upsheren, not cutting a child’s hair until his third birthday, has its origins in the prohibition against eating a tree’s fruit during the same amount of time.
There are a few ways people observe the holiday. One is to eat specific fruits that grow in Israel: grapes, figs, pomegranates, olives and dates. Other people simply eat any “new” fruit on this day. Others celebrate by having a Tu B'Shevat seder. A sample of one can be found here in .pdf format.
When eating fruit on Tu B’Shevat, the following prayers are said:
The blessing on fruit:
Baruch Atah A-donay, Elo-heinu Melech ha'Olam borei pri ha-etz.
[Blessed are You, L-rd our G‑d, King of the universe, who creates the fruit of the tree.]
If tasting a fruit for the first time in its season, recite the Shehecheyanu blessing before saying the fruit blessing:
Ba-ruch A-tah Ado-nai E-lo-he-nu Me-lech ha-olam she-heche-ya-nu ve-ki-yi-ma-nu ve-higi-a-nu liz-man ha-zeh.
[Blessed are You, L-rd our G‑d, King of the universe, who has granted us life, sustained us, and enabled us to reach this occasion.]
-- April http://agru.etsy.com/