Those who have learned to listen to trees no longer want to be a tree. They do not yearn to be anything but what they are. That is home. And that is happiness.
Hermann Hesse
Driving up the hill to enter campus, the road gently arcing to the left, it’s always the trees that woo me: first, an apple orchard to the left, then, beside the first of the brick Gothic and Tudor buildings that lend this place its stateliness (or ghostliness, depending on who you ask), a row of massive pines standing sentinel, shading the small groups of patients who sometimes take advantage of the lawn. At the top of the hill, a spot Frederick Law Olmsted chose in 1872 for its expansive views of Boston and the old trees that stood here back then, I park my car under the shade of quaking aspens and red maples in a lot blowing with cottonwood seeds—duckling-soft in my palms—and march towards the Admissions building, not to check myself in, this time, but to spend part of my sabbatical year researching in their archives.1 It’s taken more than two years to get access. I cannot wait. And at the same time, I’m anxious to have returned to a site where I was once so sick.
In New England, McLean is often thought of as a hospital for the elite, once housing literary giants like Robert Lowell, Sylvia Plath, Anne Sexton, musicians Ray Charles and James Taylor, and, more recently, Selena Gomez, and NFL star Brandon Marshall. Admittedly, when it was time for me to go (my stay was entirely covered by my free Massachusetts health insurance), I told myself this was the best place in the world for the treatment of Obsessive Compulsive Disorder, and that its reputation and legacy meant I’d get my greatest shot at overcoming the disorder. All of that turned out to be true. I have been very lucky. My treatment team was incredibly skilled and experienced. They saved me. Or, as they say, they helped me save myself.
But today, looking back, I think that it was also this place—its beautiful landscape, the old trees, feeling apart from the world in a wind-blown sanctuary—that played a role in my healing, too, and that maybe the hospital’s nineteenth century founders deserved some credit as well. Twelve years later, when I return to campus, my first impulse is to say hello to my old friend, my favorite oak tree, which has stood rooted in the bowl since the hospital’s founding. I know because all year, I’ve been obsessively tracing it back in time, scrutinizing old photos and lantern slides to track its growth since 1895.
McLean’s trees might seem like a trivial piece of this centuries-old institution’s history. But my interest is rooted (pun intended) in the hospital’s most fundamental principles, which have been carried forth into the present day: the Moral Cure, a humane approach to mental healthcare that’s grounded in treating patients with kindness and helping them to heal with architecture, the environment, and access to the work and hobbies that fuel their bodies, minds, and spirits.2 Today, in the wake of the ongoing pandemic and rising anxiety and depression, we espouse the benefits of “tree bathing” and spending time outdoors, away from our tech and devices.3 McLean’s campus offers a living map of the history of psychiatry’s value of the natural world in patient care. I’ve never been good at memorizing names and classification systems, but lately, I’ve been trying to know natural places more intimately by learning to differentiate between species. It started five years ago with a walk in Michigan under the trees, when I asked a friend to help me. I was embarrassed that I didn’t even know which were maples and oaks. A Canadian scientist, she said to think of the Canadian flag, maple syrup: a stouter leaf. Oaks, on the other hand, she said, are shaped like our hands. She stretched her fingers across a leaf. I did the same, my fingertips reaching to the edges of a leaf’s lobes, mimics of each other (we both have large palms and long, thin fingers). Robin Wall Kimmerer writes about the importance of knowing species’ names, even if they’re only the names we make for them, distinguishing one from another.4
When I was a patient at McLean, I didn’t know the type of tree I’d been sitting under for weeks. I only knew it brought me comfort. The 1960s patient map I’m given over a decade later tells me it’s a white oak, and when I go back now, I marvel at its leaves that reach and flutter like thousands of hands in the air.
Like the naming of species and taxonomies, diagnosis is a linguistic process based on defining characteristics. The year before I went to McLean, I’d found myself in the Alice-in-Wonderland state of being thrust into a new world because my body and past had changed with sudden knowledge. At thirty-two, I told someone my symptoms, and she gave me new words, a diagnosis: OCD, Obsessive-Compulsive Disorder. She might as well have said, Here is a different story of your life.
From the time I was eight or nine, when the intrusive thoughts began to torment me, I thought I was secretly a monster, and that one day, I’d go insane and be locked up forever. When I finally learned that I didn’t have a case of secret sociopathology but a treatable anxiety disorder, I was floored—both relieved and disillusioned: I’d spent twenty-two years avoiding much of what I wanted simply because of what I now know was just OCD? How could I not have known? How could I have wasted so much time? And now that I was so sick, how on earth was I going to get better?
My life unspooled behind me in a shape I couldn’t narrativize. I lost my ability to write. Isolated in my apartment, I made fabric pictures, intuitively trying to make stories out of my overwhelming experiences and feelings.
I spent a year and a half in darkness, lost, trying to do OCD treatment but feeling like it was so deeply rooted throughout my body, it was futile. Attack it in one place, it grew in another. Working hard to stay alive, I spent time outside, under the trees with my dog, and I went to look at art. Having planned my own death one winter day, I found myself at the Depressions Clinic, a day program at McLean. Finally, here I was in the sort of place I’d always believed I’d end up: the mental hospital, as I thought of it, an image that came from 1970s pictures of neglected people languishing in over-crowded halls. I had no idea that a place like McLean existed. I found not anguish but high-quality care, the halls filled with people like me, working to heal, and even, often, laughing. I survived that winter, and in May, I checked into the OCD Institute at McLean. This, I knew, was my chance. And it was terrifying: now, I’d have to face down every single fear.
On my return to McLean’s archives last year, I dove into researching the history of the hospital, combing history books for accounts of its development, seeking the sources of its impact on me. In 1811, the Massachusetts General Hospital Trustees voted to open McLean Asylum for the Insane in Somerville, at the Barrell Mansion, a site selected for its bucolic attributes: fields that sloped gently towards Millers River, tall trees, and beautifully manicured gardens.5 Patients could be ferried between the hospitals by boat, food shipped from the farm at McLean to Mass General. According to contemporary historians, by the 1870s, McLean was forced to find a new location because it was being overrun by the expanding railroad system in Somerville. A few months later, Evelyn Battinelli, Executive Director of the Somerville Museum, corrects me.
“It wasn’t just the railroads,” she says. “The bigger problem was the pollution from the quickly growing meatpacking plants that were built around the asylum,” she says. “The plants were disposing of carcasses in Miller’s River, and it got so bad, McLean had to move.”
I go back to newspaper articles and accounts from the 1870s, and read that factory managers believed the tide would carry the animal remains out of the estuary. They were wrong. The river was soon overrun, in what one resident described as a “fetid” mess.6 Immigrants who lived in the neighborhood to work in the factories and plants were made to endure the stench and unsanitary waters until the town was mandated by the state government to fill the river and create an underground container for the carcasses—the first U.S. environmental law.7
The Barrell Mansion and Cobble Hill were levelled: trees razed, the hill used to fill in the river, patients transported in 1895 under the cover of a series of carriage rides to the Belmont site. Relocation complete. “One by one,” Reverend Edward G. Porter writes in the 1896 Massachusetts Historical Society Proceedings, “the natural beauties of our metropolis are giving way to the imperious demands of our commercial growth … this well-known eminence just over the river must not only surrender its half-dozen large and well-built structures of brick and stone, its stately elms and its terraced gardens and orchards, but the hill itself is at once to be levelled to make room for a network of tracks and freight yards.”8 Industrialization was unstoppable. Walk around the Somerville site today, and you’ll find desolate concrete flatlands dominated by the railroad hub, high-rises moving steadily upwards all around, locals still shaking their heads at the swiftly changing neighborhood.
The trustees asked Frederick Law Olmsted, who had just designed the mental hospital in Buffalo, to choose between three sites. He selected Belmont for its rolling hills, old trees, “long curves and easy glades,” as he wrote, and a glorious, open horizon over the treetops that stretched to Boston. Stand at the entrance of the Administration building today, and you’ll feel like Dr. Cowles, the Superintendent who oversaw the campus he helped design, looking out across the bowl, the expansive treetops (and, now, the condominiums) towards the city.9
In the course of carefully selecting this site and preparing it for patients, the trees were thinned on Olmsted’s advice, per his 1872 letter about the site, and others were planted, the ground levelled in places and graded, working around the rocky outcroppings, to make the place a healing environment for patients to walk and wander. A McLean bulletin article from the 1970s notes that when the Belmont site opened in 1895, “A variety of hardy New England trees—cedars, oaks, maples, and hemlocks covered the 107 acres.”10
The buildings took three years to construct. They were designed like a college campus, with buildings spread out across green space between old trees, under what was called the “cottage plan,” which allowed for the separation of patients depending on severity of illness (and level of noise), as well as space for natural interludes outdoors for walking and relaxation.11 Olmsted planned for the buildings to be connected by tunnels that rise above ground and divide the landscape into courtyards.
Olmsted may or may not have been involved in the details of the landscape design. On the record, that was left to Joseph H. Curtis. Although Olmsted wrote that he dreaded ending up in an institution, he would return to McLean as a patient for the final five years of his life.
One of the terrible things about OCD therapy is that you have to suffer so much to get better. It’s such a cliché: the only way out is through, but for OCD, that’s how it works. Exposure-response-prevention (ERP) means you make a hierarchy of all your fears and obsessions, from least to most scary, and you slowly work your way up the list, facing down every single one. You invite the very worst things to happen. You don’t allow yourself to ritualize. It’s like lying down on a train track and waiting for the train to approach, forcing yourself to stay there, feeling its rumble. You cannot move. The anxiety rises and rises. Before the anxiety begins to abate, ERP feels like torture.
During breaks, I’d go back to my room intending to read a stack of books lent to me by my friend Ellen—Gretel Ehrlich, Amy Blackmarr, Janisse Ray—women who write about the natural world—then quickly fall asleep. I was always exhausted. But one day, I wandered outside. I walked across the patio, over the driveway, and into the bowl, towards a massive tree. It sits at the bottom of that easy hill. It was calling to me, graceful branches reaching out like a mother’s arms: I’m here; you’re safe. Close your eyes and listen to my leaves.
Leaning against the tree, I could feel its thick bark. I knew it had seen many more years than I had, that its roots had reached deep into the earth, emerging here and there in the grass like strong, gnarled fingers spanning the width of its canopy. It had a strength I longed for, a sense of certainty—something most people with severe OCD almost never experience. It was solid. And forgiving. Both at once. It was what I was striving to be.
Thinking about my time under my favorite tree, as I came to call it, reading the tree map made by patients in 1965-66, considering Olmsted’s involvement, and in search of information about the materials used to construct the buildings, I knew I wanted to write an environmental history of McLean. But, my first few months in the archive, I still hadn’t found much about the landscape—until one day, the archivist sent me an email saying, “I left something on your chair I think you’ll be interested in.” I raced to the archive in the morning to find Margie A. Lamar’s “A Study of the History of Landscape Architecture” at McLean.12 Between the 1970s and 2022, Margie A. Lamar’s paper was internally referenced in hospital publications, but never published beyond its walls.
Why did she do this research, and never publish it? Who was she, a woman researching McLean in the 1970s?
Lamar opens her paper by citing Olmsted at the end of his life, back at McLean as a patient: “they didn’t carry out my plan, confound them!” She credits this quote to Laura Roper’s biography of Olmsted, published in 1973 to wide acclaim for its breadth and depth.
Roper had been working on her biography of Olmsted, F.L.O., since the 1950s, though it wouldn’t be published until 1973. Lamar wrote her paper in 1975 as part of her work for a class on landscape architecture that she took at Harvard with Albert Fein, one of the leading experts on Frederick Law Olmsted.
On April 25, 1975, Laura Roper visited Fein’s class, and told Lamar that Olmsted did design McLean’s campus. Included in Lamar’s paper is a reference to “a watercolor sketch, which is, quite probably, the work of Olmsted. It shows the arrangement of the patient buildings around the Administration Building spaced from 55 to 65 feet apart with a ‘Pleasure Ground’ area indicated, and connected walkways. It is dated November 1875 and is marked ‘Study No. 2.’” Lamar defends her claim that this is likely Olmsted’s work with reference to several letters he wrote to McLean’s trustees and Joseph H. Curtis about the site and design.
Lamar wrote that she hoped that her paper would “contribute in some way to the appreciation and preservation of Olmsted’s work at McLean Hospital.” She is surprised that, as of the writing of her paper, he hasn’t been recognized for his design of McLean in any publications.
After closely analyzing the differences between Olmsted’s original plan and McLean’s construction, completed in 1895, Lamar determines that, when he said he was dismayed at the hospital deviating from his plans, “he must have [been upset about] this difference of opinion about the placement of the buildings, their distance from each other, and their arrangement around a village-green.” She says that it was Dr. Cowles who was largely responsible for “the ultimate placement of the buildings. In reading the trustees reports and the histories of McLean, it is obvious he was a very able and forceful man.” In addition, she adds that mental hospitals had to be designed by “‘experienced medical men.’” This was because of the rules created by the group now known as the American Psychiatric Association, of which, she says, Cowles was president “at one time during his tenure at McLean.” This may have been why Cowles was credited with the design rather than Olmsted. Lamar further suggests that Cowles and the trustees “may have felt Olmsted’s original ideas reminiscent of the Buffalo State Hospital,” which Olmsted had also designed and was in keeping with the state hospital aesthetic, which McLean was “trying to avoid.”
In her introduction, Lamar describes the treatment of mental health in 1872 to have been shaped by “Moral Management,” as defined in the late 1700s by Samuel Tuke in England and Phillipe Pinel in Paris. Patients were to be taken to “proper asylums … a calm retreat in the country is to be preferred. When convalescing, allow limited liberty; introduce entertaining books and conversation, exhilarating music, employment of the body in agricultural pursuits.” Instead of being sent to the jails or poorhouses, Lamar writes, “[a]t last the mentally ill were to be treated with kindness in separate institutions.” This was the case the Mass General trustees had so fervently made in the campaign to found McLean.
McLean offered all the benefits the Moral Cure espoused, in Somerville and then Belmont, sending patients for walks and time in glorious gardens and under the trees, and assigning them to work in the stables and on the farm, which provided food for both McLean and Mass General Hospital. In the 1960s-70s Disability Rights Movement, such work was outlawed, because it allowed institutions to take advantage of vulnerable people’s free labor. But, as Oliver Sacks observed in the 1990s, this also took away many patients’ sense of purpose, the worthy contributions they could make between therapy sessions and group meetings, and the chance to stay physically active in camaraderie with other patients and staff.13 Now, they were left to their own devices, often listless on the wards.
Lamar says she found little about the source of McLean’s trees, but that Joseph Curtis, appointed one of the leads on the project by the trustees, was “… an engineer for several subdivisions in Belmont from 1872–1910,” and might have transplanted trees slated for “removal” from those sites to McLean. Construction files at McLean reveal that in 1893, Curtis contracted with the Shady Hill Nursey Company for “deciduous trees, vines, and shrubs.”14
In addition to his work around Boston, Curtis was a well-known summer resident of Mt. Desert Island in Maine, where he “co-founded the Northeast Harbor Summer Colony with William Doane and Charles Eliot, then president of Harvard University,” and designed several neighborhoods and gardens, including his own home, the Thuya Garden, Asticou Terrace, and a portion of Land’s End.15 Eliot’s son became an apprentice to Olmsted and, in 1890, petitioned to save the 400-year-old Waverley Oaks, just across from McLean’s campus, which Olmsted references in his 1872 letter to the trustees about the value of McLean’s Waverley site. Eliot’s argument resulted in the formation of The Trustees of Public Reservations, and then, in 1893, the nation’s first Parks System.16
Lamar writes that other sources of McLean’s trees included Ebenezer Francis Bowditch, one of the trustees, who would select from his “farm in Brookline … choice fruits and flowers to bring to the hospital.” In addition, Joseph Breck and Sons supplied some trees, shrubs, and flowers. Finally, Lamar surmises that because Olmsted’s firm was working on the Arnold Arboretum as of 1880, it’s possible he may have transplanted trees from there; this is the only claim without any direct evidence. She writes that “Charles Sprague Sargent, founding director of the Arnold Arboretum,… [was believed to have] had a role in selecting trees for McLean,” but the source for this belief isn’t clear.
Looking back at photos from the Waverley site, this white oak has been here since at least 1895. I hold a lantern slide up to the light of a window, squinting to see ice skaters in the bowl, next to the tree. Because of its large size even at that time, it must have been one of the trees native to this site, one of the survivors in Olmsted’s plan to “thin” the wooded landscape into glades.
I take a break from hunching over the table at the archives and snapping photo after photo to document, to slip outside into the sun, and walk down the hill to the old oak. I find a broken bird’s egg, the yellow yolk dried inside, and a colony of mushrooms spread out in the shade, making new life. I sit and lean against the bark, listen to the leaves, embracing what always feels, here, like respite from the rest of the world—quiet, rest. Olmsted was right. This landscape does bring patients—at least, me—a sense of tranquility.
Thirteen years ago, at a time when I was being schooled in mindfulness as a way to overcome severe anxiety, I came to this oak for respite, and for lessons. Stand here. Listen. The leaves are moving, the grass is growing, the sun and clouds are shifting above you, written in the shadows that pass over your legs. Faith is a radical act, the ability to believe in what you can’t see happening. Faith not in the religious sense but in the spiritual—faith that the world is “not one long string of horrors,” as the poet Gerald Stern writes, but ultimately good, that the sun will rise in the morning, that I would survive this time and emerge on the other side. My treatment providers pointed me out of the dark forest in which I was trapped, and I walked, blind, listening to their voices, following every instruction. It took all of my energy to fight, believing my team knew how to get me through. In my downtime, I sat under this tree, feeling still but knowing its cells were multiplying and expanding as I leaned on a trunk that looked and felt massive, immobile, and permanent. This tree couldn’t possibly be moving. But it was.
There’s something satisfying about science confirming how good it feels to breathe in the air under tall trees, that sift in the body that comes after a walk in the woods.
Researchers have known for decades that walking under trees benefits our health. The pandemic and our time forced outdoors popularized the Japanese concept of shinrin-yoku or forest bathing, “walking under the trees and breathing the air” or “immersing oneself in nature, using one’s senses.”17
A 2022 survey of the shinrin-yoku literature found that the most accurate results document the benefits for people suffering from anxiety and depression. That research is now expanding to assess the effects on people with other mental health challenges, including those at mental hospitals.18 Other scientists have documented the value of monoterpenes, chemicals emitted by certain plants that decrease our stress levels.19
There’s something satisfying about science confirming how good it feels to breathe in the air under tall trees, that shift in the body that comes after a walk in the woods. That feeling of calm is now documented: We are being changed at the molecular level.
This recent science confirms what psychiatrists and health care providers have known for centuries: trees benefit our health. These were all the same prescriptions given by the founders of the hospital in the days of the Moral Cure. Looking at 1880s photos from the Somerville site, we see women standing under the trees with walking sticks, waists cinched in their dresses. A group looks over the edge of a bridge at the pond below. They also spent time weaving in the loom room, looking at art in a space curated by one of the trustees, playing tennis, and ice skating. And just as women at McLean were told to do in the 1850s, when I was at McLean in 2010, we were taught to get outside, move our bodies, and practice what we call today mindfulness, focusing on the present moment. We took up hobbies we’d lost along the way.
Those traditions gained even more force in the 1960s. In the midst of the national environmental movement that had begun to take hold in the wake of publications such as Rachel Carson’s Silent Spring, patients Ann Lord and Stewart Sanders collaborated with trustee Mrs. Charles A. Coolidge to make a remarkable map of the trees of McLean. Coolidge lived right across the street from McLean in the 1930s while raising her children with her husband, Charles Coolidge, Jr., a descendant of one of the architects who designed many of McLean’s buildings. Charles, like his wife, seemed to be committed to preserving the town’s natural spaces, as he served on the new Belmont Conservation Commission in 1967.
Perhaps the Coolidges were inspired by the revival of interest in Olmsted’s work in the 1950s and 60s, which, writes the editor of Fein’s 1972 book on Olmsted, “a group of scholars … are chronicling and illustrating … for the benefit of the new environmentalists—for many of whose ideals Olmsted is the prototype.” Fein writes that it’s only natural that Olmsted should be revisited in the wake of the “three major crises undergone by this nation during the last decade—racial, urban, and ecological.”20
Today, with the ongoing Black Lives Matter movement, the mental health crisis brought on by the pandemic, and the climate crisis, we are in not so dissimilar times. We sit at another axis, the intersection of environmental and mental health research, focused on how the environmental crisis impacts all of us around the world, particularly those losing their lives and homes in the southern hemisphere. Researchers are focusing on what we can do to prevent climate change and mitigate the damage for those who are losing the most even though they hold the least responsibility for its cause.
Walking back onto McLean’s campus last year was a strange experience, jolting me back to the time I stayed at NB1, sleeping on a twin mattress in a room with a teenager who was fighting similar demons. But, just as I learned that exposure therapy brings the abatement of anxiety, allowing me to finally laugh in the face of my OCD (Take that! I began to think when an exposure was done), I found that coming back to the hospital wasn’t scary at all. It was full of stories. Just as McLean was designed to be a home, as Lamar writes, so it became one for me—first when I went to the OCDI, and now that I’ve delved into its archives and rested, again, under its trees. I have been very lucky.
For years after I left McLean, I pressed ahead, trying to make up for lost time. I had a doctorate to finish, a job to earn, tenure to race after, and finally, the exhilaration and exhaustion of single motherhood consumed me. Now, enough space has passed between the years I was sick and today, with so much other work done, that I can inhabit the space again—differently, full of curiosity.
Mama, my child asked on a recent walk through the city, when I insisted we stop and look up at a tall old oak tree, Do you wish you were a tree?
I laughed. It was a fair question. We spend a lot of time looking at trees together.
No, I say, but I do love them.
On my breaks from the archives, sometimes, I go back and visit the white oak. I sit under its ever-widening branches, marvel at the mushrooms emerging in June, peek in at the massive hollow where the trunk split apart, and then I sit and listen to its leaves for as long as I can. These days, I only have a few minutes here and there for quiet interludes.
McLean’s site in Belmont is the result of the onslaught of environmental damage caused by the industrial revolution’s second wave, with the railroads and meatpacking plants housed at the original Somerville site. The first time I drove through the old site, now called Inner Belt Park, I saw it as desolate, a contemporary wasteland, the sad castoff of industrialization. But now, returning in early spring, I see something else: rows of trees. They’re saplings, still, but someday, I hope, they’re going to line these roads as elders, and someone will walk under them, and wonder how they came to arrive here. Someone will dig around for the stories. Someone will unearth their histories. Maybe. At the very least, they’re offsetting carbon emission and improving our air, giving us shade and some beauty. Walk up close, and you’ll see the moss and lichen already forming on their bark, as if they’re all making themselves at home. This, to me, is hope.
I get up and walk away from my favorite tree, meander across campus to my car, and drive back to Somerville to wait for my child to emerge from school, into my outstretched arms.
Acknowledgement
The research conducted for this article would not have been possible without the generosity of Terry Bragg, archivist at McLean Hospital, who welcomed me to the collection and spent a great deal of time talking with me about the history of McLean and its grounds. I’m deeply indebted to him for his time and willingness to share his knowledge.
This piece is for Thea Cawley and Leslie Shapiro, with gratitude, and in memory of Dr. Mike Jenike.
Rachel May is a writer, researcher, and educator. She’s an Associate Professor at Northern Michigan University and currently lives in Somerville.
Endnotes
- Olmsted, Frederick Law. “Letter to Henry B. Rogers, Chairman of the Board of Trustees of Massachusetts General Hospital, December 13, 1872.” Library of Congress, Frederick Law Olmsted Papers: Subject File, 1857–1952; hospitals, mental, 1860–1887, Images 10–18, https://www. loc.gov/resource/mss35121.mss35121_025_0560_0631/?sp=10&st=image&r=0.208,0.033,0.957,0.48,0
- Yanni, Carla. The Architecture of Madness: Insane Asylums in the United States. Minneapolis: University of Minnesota Press, 2007.
- Song, Chorong, et al. “Psychological Benefits of Walking Through Forest Areas,” International Journal of Environmental Research and Public Health. Dec. 10, 2018 (12): 2804. 10.3390/ijerph15122804
- Kimmerer, Robin Wall. Gathering Moss: A Natural and Cultural History of Mosses. Corvallis: Oregon State University Press, 2003.
- Sutton, S.B. Crossroads in Psychiatry: A History of the McLean Hospital. Washington, DC: American Psychiatric Press, 1986.
- Morris, Dee and Dora St. Martin, Somerville, Massachusetts: A Brief History. Mount Pleasant, SC: The History Press, 2008.
- Porter, Edward G. The demolition of the McLean Asylum at Somerville: with an account of its original buildings, formerly the seat of Joseph Barrell. Cambridge: John Wilson and Son University Press, 1896. National Library of Medicine Digital Collections: Medicine in the Americas, 1610–1920. https://collections.nlm.nih.gov/catalog/nlm:nlmuid-101741018-bk
- Olmsted, Frederick Law. “Letter to Henry B. Rogers, Chairman of the Board of Trustees of Massachusetts General Hospital, December 13, 1872.” Library of Congress, Frederick Law Olmsted Papers: Subject File, 1857–1952; hospitals, mental, 1860–1887, Images 10–18, https://www.loc.gov/resource/mss35121.mss35121_025_0560_0631/?sp=10&st=image&r=0.208,0.033,0.957,0.48,0; Noll, Richard and Kenneth S. Kendler, “Edward Cowles (1837–1919),” American Journal of Psychiatry, “Images in Psychiatry,” October 1, 2016. https://doi.org/10.1176/appi.ajp.2016.16060636
- Lamar, Margie A. “A Study of the History of Landscape Architecture: McLean Hospital, Belmont, Massachusetts, A Research Paper Presented to: Professor Albert Fein, Harvard Graduate School of Design, Spring Term 1975.”
- Brown, Sarah, ed., Laurie Beckelman, Elena Velante. “The Trees at McLean: Their Roots Stretch Back 100 Years,” The Bulletin, McLean Hospital, November [1978]: 4, McLean Hospital Archives.
- Olmsted, Frederick Law. “Letter to Henry B. Rogers, Chairman of the Board of Trustees of Massachusetts General Hospital, December 13, 1872.” Library of Congress, Frederick Law Olmsted Papers: Subject File, 1857–1952; hospitals, mental, 1860–1887, Images 10–18, https://www.loc.gov/resource/mss35121.mss35121_025_0560_0631/?sp=10&st=image&r=0.208,0.033,0.957,0.48,0
- Lamar, Margie A. “A Study of the History of Landscape Architecture: McLean Hospital, Belmont, Massachusetts, A Research Paper Presented to: Professor Albert Fein, Harvard Graduate School of Design, Spring Term 1975.”
- Payne, Christopher and Oliver Sacks. Asylum: Inside the Closed World of State Mental Hospitals. Cambridge: The MIT Press, 2009.
- Joseph Curtis to Edward Dwight, Esq., January 23, 1893, Construction Records, Folder “Grounds III,” McLean Hospital Archives.
- “Joseph Henry Curtis (1841–1928),” The Cultural Landscape Foundation, https://www.tclf.org/pioneer/joseph-henry-curtis; “History of Thuya Garden,” Land and Garden Preserve, https://www.gardenpreserve.org/history-of-thuya-garden; Hewlitt, Betsy. “Getting the Story Straight: Joseph Henry Curtis,” Land and Garden Preserve, https://www.gardenpreserve.org/post/archives-joseph-curtis
- Eliot, Charles. “Waverley Oaks,” Garden and Forest Magazine, Ed. Charles S. Sargent. February 1890 (III: January to December, 1890). Library of Congress. Volume 3. https://www.loc.gov/resource/gdclccn.05040093_v03?r=-0.62,0.442,2.24,0.985,0; Lynn, E. “Charles Eliot: An Early Leader of the Environmental Movement,” Olmsted Network. https://olmsted.org/colleagues-firm/charles-eliot/
- Kotera, Yasuhiro, Miles Richardson, and David Sheffield. “Effects of Shinrin-Yoku (Forest Bathing) and Nature Therapy on Mental Health: A Systematic Review and Meta-analysis,” International Journal of Mental Health and Addiction. July 28, 2020 (20: 337–361). https://link.springer.com/article/10.1007/s11469-020-00363-4
- Bielinis, Ernest, Aneta Jaroszewska, Adrian Lukowski, and Norimasa Takayama. “The Effects of a Forest Therapy Programme on Mental Hospital Patients with Affective and Psychotic Disorders,” International Journal of Environmental Research and Public Health, Dec. 23, 2019: 17(1):118. https://pubmed.ncbi.nlm.nih.gov/31877954/#article-details
- Donelli, Davide, et al. “Effects of Plant-Emitted Monoterpenes on Anxiety Symptoms: A Propensity-Matched Observational Cohort Study,” International Journal of Environmental Research and Public Health. 2023, 20, 2773. https://doi.org/10.3390/ ijerph20042773
- Fein, Albert. Frederick Law Olmsted and the Environmental Tradition. New York: G. Braziller, 1972.