Tu Bishvat, the 15th of the month Shvat, is indeed coming: hag la-ilanot (the holiday of – or for – the trees). In Israel people will be busy planting – or buying certificates for – trees. Maybe it really should be called “the holiday of Keren Kayemeth [LeIsrael],” the time when that institution takes the spotlight and benefits from increased contributions. This planting of trees is a modern idea, a Zionist invention that really caught on and transformed Tu Bishvat completely. Some people may also be busy buying fruits of the land to eat that day and may even have a Tu Bishvat Seder – eating fruits, drinking wine and somehow celebrating the land in a custom that sprang up through the influence of Kabbalistic writings. What is actually the origin of this day – which is really not a ‘holiday’ at all, just a date on the calendar?Tu Bishvat is not mentioned in the Torah or elsewhere in the Bible. It is found first at the very beginning of Mishnah Rosh HaShanah where there is a list of four different “New Year” times – a New Year on the first of Nisan for the reign of kings and for the festivals, a New Year in Elul for the tithe given for cattle, the New Year for the year itself in Tishrei, the New Year for trees on the first of Shvat, i.e. for tithing the fruit of the trees according to the House of Shammai. The House of Hillel says that it is on the 15th of Shvat. That date is unusual, since all the others are on the first day of the month and requires some explanation. Prof. Louis Ginzberg, the great Talmudist, suggested that this reflected the economic status of the two houses. Hillel represented the poorer people and Shammai the richer ones. The trees of the wealthy were planted in areas where they blossomed earlier, therefore it made sense to start their year earlier on the first. Hillel’s followers were located in places that were higher and colder and bloomed later, therefore it was natural for them to count them only from the 15th. The Mishna does not give any reason for their disagreement, however, and some authorities, like Rabbi Akiva, were not even certain which date was really taught by the House of Hillel (see Talmud Rosh HaShanah, 14b).In any case, it is absolutely clear that the new year for the trees in Shvat has nothing to do with planting trees. It refers only to the date regulating when we begin counting the year in which trees bear fruit and not with the eating of the fruit. It is not even a holiday, just a date for the determination of what year the fruit can be used for tithing. Akiva and the other Sages living in those times would not have known what you were talking about if you suggested going out to plant a tree at that time or sitting down to a special meal on that day. That particular custom was instituted by the 16th century kabbalists of Safed who taught, among other things, that eating those fruits would nullify the bad effects of Adam and Eve eating the fruit from the Tree of Knowledge. Planting, as was already mentioned, was an invention of early 20th century Zionism. The land of Israel was practically devoid of trees at that time and turning Tu Bishvat into a kind of Arbor Day was a great way to tackle that problem and remains so even today. Recently, attempts have been made by Jewish groups concerned with environmental issues – surely one of the most vexing problems of our age even if some prominent leaders try to deny it – to use this day as a time to teach Judaism’s position concerning care for the earth, for the environment, for nature. They stress the fact that when God places Adam in the garden of Eden, He does so that Adam – the human being – will “till it and tend it” (Genesis 2:15). The Hebrew root for ‘tend’ is sh-m-r, which means to guard and care for. That is what environmental concern is all about – guarding and caring for this planet, which is our home. Is it a stretch to make that part of the observance of Tu Bishvat? No more so than eating fruit or planting trees – and certainly as important.What is really crucial is not what we make of the day of Tu Bishvat, but what we make of our world all year long – our care of this wonderful planet that sustains life but that can be ruined by our carelessness. Our planet is in danger from the deliberate actions taken by commercial interests who are more concerned with making profits from oil, coal, automobiles, and so on than with the preservation of life on earth. Also problematic are leaders who kowtow to these interests either out of ignorance or out of greed. So how will you celebrate Tu Bishvat this year? Planting trees, eating fruit, having a special seder, tending to the environment – or perhaps all of the above? ■The writer, a former president of the International Rabbinical Assembly and the founding director of the Schechter Institute, is a member of the Committee on Jewish Law of the Rabbinical Assembly. A prolific author, two of his books have received the National Jewish Book Council Award as the best work of scholarship of the year. His most recent book is Akiva: Life, Legend, Legacy (JPS).