Three years ago, unknowingly just before the pandemic, I decided to switch up my teaching at Harvard. Perhaps unbeknownst to many, in addition to being the Director of the Arnold Arboretum, I am also the Arnold Professor of Organismic and Evolutionary Biology at Harvard University. Like all professors, I teach undergraduate classes, lead a research group with graduate students, and am charged with helping young minds begin to self-conceptualize a life that will be rich and rewarding. But rich and rewarding in what ways?

For many years, I taught a freshman seminar called “Getting to Know Darwin,” in which thirteen students, a graduate teaching fellow, and I explored Charles Darwin’s life from his medical school days in Edinburgh (he dropped out) through old age. Each week we focused on a particular topic, read some of his varied correspondence related to that topic, and then put ourselves in his skin and carried out an experiment or set of observations that he himself made. We visited pigeon fanciers, dangled duck’s feet (bought frozen in Chinatown) in small ponds to see what climbed aboard, brought earthworms to the New England Conservatory to see if they could hear a bassoon or piano (they can’t) , and generally engaged in following Darwin’s passions. And passions are indeed what lie at the heart of Darwin’s rich and rewarding life—one that was rich in family, friends, and perhaps most rewarding, in having devoted his life to a full immersion in the mysteries and beauty of nature. The first-year students may have thought they were going to learn about a “biographical” Darwin, but my simple goal in this class was for them to learn how one can discover a path in life that is fulfilling. Rather than choosing a career, discover what you are passionate about and stick to it.

After seven years of Getting to Know Darwin, it was time to venture forth and create a new freshman seminar. This time, I wanted my students to explore how we can deepen our lifelong relationships with the natural world. I entitled the course “Tree” and held my breath to see if anyone would join. I worried that most first-year college students would already be focused on which classes they “needed” for their chosen concentration and career. Who would have time to spend a semester thinking about trees and how one might form a unique and personal relationship with trees and nature writ large?

Imagine my joy when nearly 90 students applied for the thirteen slots in the class in 2020. Now, three years on, the class continues to reap huge numbers of applicants and each year, thirteen wonderful first semester freshmen, just out of high school, with their lives entirely ahead of them, continue to reinvigorate my sense of optimism that the next generation will do far better than mine in stewarding the planet and its biodiversity. So, what is in the freshman seminar “Tree?” Here is the formal description: 

In an age of environmental destruction and outright murder of our biological brethren, there is something deeply troubling about humanity’s relationship with nature. Technology has left us with mere facsimiles of nature—pixilated abstractions of biodiversity through satellite imagery, decoded strings of DNA—and we, as a species, have become fundamentally disconnected from actual nature and the magnificent organisms with which we share the earth. In this seminar, we will work to understand and give agency to trees as individual organisms, literally rooted in the ground, and evolutionarily rooted in deep time…. to initiate a personal and lifelong connection with the “other,” the vast and varied organisms with which we share the planet.

During the semester, we read literature, poetry, law (can a tree have legal standing?), and biogeography (the evolutionary historical migrations of trees around the world); we ponder tree longevity (coring a tree on the grounds of the Arboretum to read the rings and see environmental history and climate change recorded in the very cells). We ask why leaves of temperate trees turn red and/or yellow in the fall (we’re not exactly sure), and why North America has so many more red-colored fall species than does Europe. We ponder the cultural significance of a handful of pecans given by an enslaved mother to her enslaved daughter as she was sold and carried forever from her family. And we observe. Each student picks an individual tree at the Arnold Arboretum (out of 16,000 accessioned woody plants!) to observe each week and report on to the class. We visit these trees collectively, and we reflect on why these trees can bring so much joy and arouse our sense of the beauty and mysteries of the natural world. And interestingly, each year these trees have become a set of gathering places for Tree students to invite their friends to meet “their” trees. In a time of Covid-induced human isolation, these trees have become social networkers!

We reflect on why these trees can bring so much joy and arouse our sense of the beauty and mysteries of the natural world.

In the final analysis, I created this course based on my fervent belief that if each of us can learn to love non-sentient individuals such as trees, we can build up our abilities to be empathic to all of nature, and beyond that, to all of our fellow human beings, no matter how different we may seem to each other.

Perhaps the single reading that sums up what I seek to accomplish in Tree is the remarkable short story by Carson McCullers, “A Tree, A Rock, A Cloud.” In this story, set in the mid-twentieth century, a transient recounts to a young paperboy his failed attempt at marriage and love of a woman.

“Son, do you know how love should be begun?” 

The boy sat small and listening and still. Slowly he shook his head. The old man leaned closer and whispered: 

“A tree. A rock. A cloud.… 

“For six years now, I have gone around by myself and built up my science. And now I am master. Son. I can love anything.… And anybody. All stranger and all loved! Do you realize what a science like mine can mean?”

I encourage all of you reading this issue of Arnoldia to continue your journeys to meet and love nature, one tree at a time. While a tree (or a rock or a cloud) cannot love us, our unreciprocated love of a tree may perhaps be one of the most unalloyed forms of empathy that we, as humans, are capable of. And I am certain that if everyone on the planet had the opportunity to learn to love a tree, the world would be a very different and better place.


William (Ned) Friedman is the eighth director of the Arnold Arboretum and the Arnold Professor of Organismic and Evolutionary Biology at Harvard University.


From “free” to “friend”…

Established in 1911 as the Bulletin of Popular Information, Arnoldia has long been a definitive forum for conversations about temperate woody plants and their landscapes. In 2022, we rolled out a new vision for the magazine as a vigorous forum for tales of plant exploration, behind-the-scenes glimpses of botanical research, and deep dives into the history of gardens, landscapes, and science. The new Arnoldia includes poetry, visual art, and literary essays, following the human imagination wherever it entangles with trees.

It takes resources to gather and nurture these new voices, and we depend on the support of our member-subscribers to make it possible. But membership means more: by becoming a member of the Arnold Arboretum, you help to keep our collection vibrant and our research and educational mission active. Through the pages of Arnoldia, you can take part in the life of this free-to-all landscape whether you live next door or an ocean away.

For more tree-entangled art, science, and writing, subscribe to Arnoldia by becoming a member of the Arnold Arboretum.