If Pesach is a major festival, and Purim a minor one, then Tu Bishvat, the New Year for Trees, which falls next Thursday, is a division-three event in the Jewish calendar. But it is one whose popularity has grown in recent times.

The biblical prohibition against the wanton destruction of fruit trees reflects their importance as sources of food and shelter in antiquity. But we now understand the vital role trees play in the environmental scheme of things, maintaining an hospitable atmosphere for us to live on the planet. So the 15th of Shevat has become a focal-point for eco-Jewish awareness.

If today there is a universal dimension to Tu Bishvat, there is also a more particular one. It is a festival that celebrates, too, the connection to the Land of Israel. Planting a tree is one of the ways we mark it, but the practice really took off in the early days of Zionism when it became a Jewish Arbour Day, embodying the effort to reclaim and renew the Land.

It has long been a tradition to eat 15 fruits on the day (some say 30) and fruits from the Land of Israel were prized. Since it wasn’t so easy to get fresh fruit from the Holy Land in bygone times, one custom was to include dried carob. The fruit has a homiletic significance: carob trees take a long time to mature and as chabad.org explains, they represent the “importance of patiently investing in the future even when it is a long and arduous process”.

It is a festival that celebrates the connection to the Land of Israel

But there is another association with the Land of Israel. Holding a Seder for Tu Bishvat, modelled on the Pesach prototype, is a custom that has become more common in recent decades. It originated among the kabbalists of Safed, who made the Northern city a centre of Jewish mysticism some 600 years ago. The Seder not only reminds us that there was a Jewish presence in Israel during the many years of exile but that it had an impact on the rest of the Jewish world.

Safed’s illustrious residents included Rabbis Joseph Caro, author of the Shulchan Aruch — the Code of Jewish Law, Moses Cordovero, author of the mystical work The Palm Tree of Deborah, and Isaac Luria, the Ari, who creatively refashioned kabbalistic cosmology. As the Encyclopedia Judaica notes, the development of Kabbalah there was “the last movement in Judaism to have such a wide scope and such a decisive and continuous influence on the diaspora as a whole”

The Seder spread to Sephardi communities but only in modern times did it catch on among Ashkenazim. The first text of a Seder known as Pri Etz Hadar (“fruit of a goodly tree”, the biblical allusion to the etrog used on Succot) was printed in the early 18th century but it was controversial because it was extracted from an earlier anthology attributed to Rabbi Nathan of Gaza, champion of 17th-century Pseudo-Messiah Shabbetai Zvi. For later rabbis, anything to do with the messianic debacle was problematic.

There are translations available but the text is difficult to understand since it is shot through with esoteric references. According to one tradition, eating the fruit on the festival represents a tikkun, a repair, for Adam’s sin in eating from  the Tree of Knowledge. Still, there are passages that can be used today by the kabbalistically uninitiated, such as the wish, “May all Creation return to its original strength and may we see the rainbow rejoicing in its colours.”

Dried carob, which it was customary to eat on TU Bishvat

Whereas on Pesach we follow an authorised format, there is no prescribed ritual for a Tu Bishvat Seder, which leaves plenty of scope for DIY flexiblitity. The usual practice is to hinge it on drinking four cups of wine a la Pesach and eating four sets of fruit. But unlike Pesach, the custom is to use both red and white wine, at times blending them.

The wine represents the cycle of the seasons, usually beginning with white, emblematic of the pale light or snow of winter; then white with a dash of red, symbolising the burst of new life in spring; then red and white in equal measures; and finally a cup of red, when autumn’s ripe fruits are available (and the leaves turn red). In a climate like ours, you might think a hot glass of mulled wine is a more appropriate start.

For the fruits, the first set is usually those with a hard shell and edible interior, like nuts. The second set consists of the reverse, fruits with an edible outside but a pit or stone inside like olive or plum or cherry. The third is made up of fruits eaten whole, such as berries. Some specify a fourth type of fruit but often the practice it is not to actually eat anything since the final fruit is said to represent the world of the spirit.

Each set of fruit carries a mystical symbolism in kabbalistic eyes but if you want to skip the more arcane ideas, some rabbis interpret them to draw more practical lessons for self-growth.

Examples of haggadot for the festival can be downloaded from the online Judaica library sefaria.org or an eco-Jewish organisation like Adamah. You can find mine sefaria for suitable readings from the Torah -— which, of course, is compared in Proverbs to a Tree of Life — and rabbinic literature.

Fruits from Israel are far more readily obtainable today than they used to be; to eat some can remind us of the Jewish people’s bond with our ancestral homeland.

The kabbalists invested the festive ceremony with messianic overtones. The Talmud, citing a verse from Ezekiel for the mountains to “stretch forth your branches and yield your fruit”, saw an abundance of produce in Israel as a sign of forthcoming redemption. The fruit that the kabbalists ate on Tu Bishvat carried the seeds of hope.