Tu B'Shvat is the Jewish "New Year" of the trees. On Tu B'Shvat we plant trees For future generations. Tu is the number 15 in the biblical numbering system (which uses the letters of the Hebrew Alphabet). B' is Hebrew for "in". Shvat is the current month in the Hebrew calendar. So Tu B'Shvat simply means the "15th of Shvat".
This year Tu B'Shvat falls on January 16, 2014, this coming Thursday.
I chose this "golden oldie" because it illustrates what I believe is a basic Jewish attitude. The blending of short-term pessimism and long-term optimism . . . packaged with a Judaic compulsion to heal the planet.