Today, many associate the upcoming holiday of Tu BiShvat with the “new year of trees.” In Israel, the holiday is even accompanied by tree plantings. Yet the holiday originally had a different kind of tree-related purpose.

Jon Greenberg is a botanist and educator who runs the website Torah Flora. A former agronomist who did research for the Department of Agriculture, he now teaches science at the Heschel School in New York City.

Greenberg links Tu BiShvat to the fiscal year in biblical times. “The day the fiscal year ended would be the calculation of tithing tree fruits” to maintain the Temple priests, he said. “It was very practical in their day.”

However, the Second Temple was destroyed by the Romans in 70 CE. “Once it was no longer applicable, other meanings began to be attributed,” Greenberg said. He noted the creation of the Tu BiShvat seder in the 15th and 16th centuries, which he connected with the rise of mysticism and Kabbalah. He also said the holiday became “a part of creating modern Israeli culture,” including families taking children on picnics and planting trees.

Overall, Greenberg said, “It’s not a major holiday, but it’s kind of fun. It’s primarily focused on trees with edible fruits.”


With the holiday coming up on Feb. 10, Greenberg shared several connections between trees and the Bible, from the Book of Genesis to Psalms.

One tree that attracted Greenberg’s interest was the Tree of Knowledge in the Garden of Eden. In Genesis, God forbids Adam and Eve to eat the tree’s fruit, but the serpent convinces Eve otherwise, and she then offers the fruit to Adam. With their new knowledge, the couple put on clothes and begin speaking, leading to God’s discovery of their misdeed and their expulsion from Eden.

Greenberg cited a “fascinating passage” from the Talmud that offers three opinions on what type of tree this could have been. One opinion, based on what Greenberg called a “purely textual” reading, posits that it was a fig tree. Another holds that it was not a tree, but rather wheat, which has “tree-like characteristics.” A third possibility is that it was a grapevine, linking Adam and Eve with the subsequent account of Noah’s Ark.

Jon Greenberg, rear, teaching biblical botany (Courtesy photo)

“There are different opinions, with differences in theology, anthropology, concepts of humanity, the growth of civilization, each represented by a different crop,” Greenberg said.

Noah’s Ark is the source of another biblical mystery—namely, what type of wood Noah used in its construction. “Genesis says Noah built the ark with a certain kind of wood, ‘gopher,’” Greenberg said. “The English translation of the Bible has ‘gopher,’ but no tree has the English name ‘gopher.’ It’s a transliteration of the Hebrew ‘gopher.’”

Greenberg said the word is “probably a reference to cypress, which would have been very elastic and resilient on the rocks of Mount Ararat. On a rocky surface, you need to have something very elastic and resilient. You would spring a leak if you collided with rocks.”

When Greenberg gives talks about biblical botany, one particular passage tends to resonate for audiences: Psalm 128.

“People seem to like the story,” he said, quoting the psalm as, “May your children be like olive trees around your table.” He explained that as an actual olive tree ages, “the wooden center rots away and becomes very vulnerable,” but younger trees “surround the old trunk” and “protect it.” That is the metaphor of the psalm, he said: Children “take care of you when you’re old, in the same way the young olive trees support [an old one].” He called children caring for elderly parents “a Bible-based Social Security system” and “a wonderful sort of cycle for family life.”

In biblical times, Greenberg said, “Everybody knew [this]; the metaphor was obvious. For us today, we have to remember, in our lives, the origin of the metaphor.”

This Tu BiShvat might be a good time to reconnect with the wisdom of nature.

“At the high school where I teach, we have a greenhouse and a garden club,” Greenberg said. “We contribute to herb sales a couple of times a year. All are positive things that make one healthier and more relaxed. We did not evolve to live in big cities. It’s a recent development.”