Jared Farmer is the Walter H. Annenberg Professor of History at the University of Pennsylvania. A former Andrew Carnegie Fellow, he is the author of several books, including On Zion’s Mount, which won the Francis Parkman Prize. He lives in Philadelphia. In his new book, Elderflora: A Modern History of Ancient Trees, Farmer surveys the complex history of the world’s oldest trees, including voices of Indigenous peoples, religious figures, and contemporary scientists who study elderflora in crisis. In a changing climate, a long future is still possible, Farmer shows, but only if we give care to young things that might grow old.