Mitzvah and tradition: when's the last time you wished a tree Happy New Year?

 The 15th day of the Hebrew month of Shevat is a great opportunity.

It's known as Tu b'Shevat, the New Year for Trees.

Why do trees celebrate their New Year so much later than ours? It has to do with the rainy season in Israel, which commences with the festival of Sukkot. It takes four months for the rains to saturate the soil, nurture the trees and coax them into producing fruit. This is important to know if you are planning to give your tithes of fruits, as we did in Temple times, because the required tithes varied from year to year. It's also important if you are a tree and looking for something to celebrate.

We humans can also celebrate along with the treesWe humans can also celebrate along with the trees. After all, the Torah says, "Man is a tree of the field." We are nurtured by deep roots, as far back as Abraham and Sarah; we reach upwards to the heavens while standing firmly on the ground; and when we do all this right, we produce fruits that benefit the world—namely our good deeds.

http://www.chabad.org/library/article_cdo/aid/615205/jewish/Tu-bShevat.htm