In reality, plants are not like humans—they are different in many significant ways, and the more that Jahren realizes this, the more she knows that humans cannot project their consciousness onto plants. In addition, humans have turned plant life into three things: food, medicine, and wood. This monetization of plant life has wreaked havoc on the ecosystem, and Jahren estimates that in 600 years, humans will have cut down every tree on Earth. Her job, then, is to track this destruction, making sure it does not go unnoticed. On her bad days, she feels helpless, but on her best days, she feels like she can do something to slow the process of global destruction of plant life.
For all of her attempts to use plants as a metaphor for her life, Jahren understands rationally that plants are not humans, and that the personification of plant life can both help and hinder their survival. She hopes to bring some attention to the destruction of plant life on Earth, though she knows that she is only a single voice and often feels frustrated by the nearly insurmountable task. This book, however, will help her to spread her message far and wide.
Jahren then directs herself to her readers again, asking that they do one thing for her: plant a tree. And then plant another. And while many people will opt for a fruit tree, like a Bradford pear, they may look nice for the first year and bloom quickly, but they are not strong or hardy, and will not last in the long term. She suggests an oak. She also mentions that many organizations have tree-planting programs and will donate trees to anyone who wants to plant one on their land. And she notes that for the first three years, the tree will need attention, as those are critical years of growth; she also suggests that readers connect the tree to their own lives, marking their children’s growth on the trunk. She also begs, half jokingly, that readers carve Bill’s name into the tree trunk as well.
Jahren finishes her memoir by returning to her conversation with readers, this time focusing on their work as scientists and conservationists. As a career professor, Jahren gives readers an assignment, suggesting that they commit themselves to action beyond the confines of her book. Not only does she suggest that her readers plant a tree, she also wants them to make a personal connection to the tree, and maybe even use its development to understand their own lives, as she has done.
Finally, Jahren notes that each reader will have his or her own tree. She asks readers to look at their trees, and wonder about them: what does it want, need, wish for? She asks that readers talk to their friends and neighbors about their trees, take photographs, count the leaves, and write it all down. That is what scientists do.
Jahren returns to the essential skill of the scientist: questions. It is only through the process of asking questions, wondering, and exploring, that scientists make breakthroughs, and it is only through the written word that they teach others about them.