In 1765 the Princeton campus was far from the verdant place we know today. Nassau Hall and the President's House (now Maclean House, home of the Alumni Council) had been built nine years earlier on four-and-a-half acres of cleared land donated by Nathaniel FitzRandolph, whose gift had allowed the trustees of the College of New Jersey to move their fledgling institution from Newark to a permanent home at last. In the intervening decade the "college yard," as the campus was called, had changed little. Those who passed along the King's Highway (later Nassau Street) looked across a bare lot at the imposing form of Nassau Hall, one of the largest stone buildings in the Colonies, and perhaps noted with pleasure the simple elegance would use today, the scene was indeed desolate. For the two buildings sat as naked as Levittown crackerboxes on the treeless hill.
It seems to have been almost as an afterthought that the trustees, at their meeting of September 27, 1765, directed one of their members to "procure a number of buttonwood trees, and send them to Princeton in some convenient time this fall; in order to be planted round the college yard." Why the trustees waited nine years to begin landscaping is anyone's guess. J. Douglas Brown '19, former dean of the faculty and the last resident of Maclean House, suggests that the prevalent feeling of the time was against trees and woodland, which harbored Indians and symbolized the wilderness the Colonist had set out conquer. Or perhaps the trustees, preoccupied with all the details of keeping their little college going were just too busy to give the matter much thought.
In any event, the "buttonwoods" or sycamores, ordered in the fall of 1765 were almost certainly planted the following spring. Two of them are still with us: the massive, gray barked pair which graces the front lawn of Maclean House. Known as "the Stamp Act trees" because at least according to legend, they were planted in commemoration of the Stamp Act's repeal in March 1766, they are the oldest trees on campus. (A much younger sycamore in the yard is a direct descendant).
These two sycamores may in fact have been the only ones planted, for the subsequent record makes no mention of any trees on the lawn of Nassau Hall until the 19th century. The French statesman Moreau de Saint-Mery visited Princeton in 1794 and, while the catalpa trees in town caught his eye, his detailed description of the college grounds focuses on their lamentable state of disregard and takes no notice of trees at all. He found the front campus "untidy and covered with the dung of the cattle that come here to raze," and the yard behind Nassau Hall "dirty and lying fallow, so that everything in the place looks neglected."
Matters eventually improved, after a fashion. At some point following 1800 the three parallel walks leading to the entrances of Nassau Hall were planted with Lombardy poplars, a stiff and spindly import which, one alumnus later notes, "disfigured the public grounds of the college." The poplars did not last long, however, and in the spring of 1825 the lawn was replanted with native species -elms, ashes, maples, and tulip poplars- in the random fashion of the Romantic School of landscape architecture. By 1837 these trees had grown large enough to make the front campus, as depicted in a lithograph from that year, not unlike our view of it today. The large tulip tree* near FitzRandolph Gate, as well as the formidable white ash opposite the Joseph Henry House, may well date from this planting.
As the campus grew over the next hundred years, trees played an integral part in the evolving landscape. The great white ashes behind Nassau Hall were doubtless planted in the 1830's, when Joseph Henry laid out the quadrangle which came to be known as Cannon Green. Later President James McCosh would move away from this formal symmetry, taking pleasure in plotting new paths and selecting sites for buildings under the park scheme which guided campus landscaping through the rest of the century. "McCosh decided he wanted the Princeton campus to look like an English gentleman's country estate, and we've been working on it ever since," says Dean Brown. The beautiful, elm-lined stretch we call McCosh Walk is a fitting tribute.
Trees were planted with new buildings such as Blair, Little, Dod, and Brown as the campus marched south in the latter 19th and early 20th centuries. By 1964 there were so many that the university commissioned a survey buy the New York landscaping firm of Clark and Rapuano, Inc., with the assistance of Dr. P. P. Perone, senior plant pathologist at the New York Botanical Garden. The survey counted 1,917 trees on the central campus, representing 140 species, but because many had reached a state of "tottering old age" or advanced disease, Perone recommended a major replanting effort. In 1966-70, some 200 new trees were planted according to the plan.
The current guardian of Princeton's trees is Harleigh Kemmerer, the university's landscape architect and manager of grounds maintenance. He directs a 41-man grounds crew, and his horticultural responsibilities include everything from indoor plants at the Art Museum the biggest and oldest trees on the front campus. Much of his effort is aimed at saving Princeton's 200 elms from the ravage of the Dutch elm disease, a fungus which was brought to the United States in 1930 in logs imported for the veneer industry and which recently wiped out the entire population of American elms on the Cornell campus. The program involves fall fertilizing and winter pruning, plus spring spraying with dormant oil (to smother the eggs of aphids and other pests) and methoxychlor (to kill the elm bark beetle, the carrier of the fungus).
Kemmerer's vigorous counterattack against the Dutch elm disease appears to be paying off. When he joined the university in 1968, it was losing 25 elms a year, he estimates. Last year it lost only one. The elms along McCosh Walk have remained healthy, for example, and the planting of beech trees among them a decade ago -- on the assumption the elms would soon die -- now seems premature. But the program has not been without incident or controversy. The spring spraying, noisily carried out by a "mist-blower" which propels the oil and pesticide to the upper branches, unleashes a torrent of phone calls to Kemmerer's office. And several years ago a biology professor's collection of blow flies, vital to his research, was accidentally killed by the spray.
Another biology professor, Henry Horn, questions the spraying and believes Princeton's good fortune with its elms may instead result from the recent mild winters. During harsh winters, according to Horn, ice may form in the old inner vessels of the elm, causing gas bubbles to embolize and block passage of water up the tree in spring. This makes the elm dependent on the new, outer vessels of the spring wood to supply its leaves with nutrients. It is these outer vessels which the Dutch elm fungus attacks. Thus the combination of a harsh winter (which forms bubbles that block the inner vessels) and the Dutch elm fungus (which blocks the outer vessels) can starve to death an otherwise healthy tree n a single season. Whether Princeton's elms are merely under reprieve, the next 10 years -- and a few hard winters -- should tell. Meanwhile, Kemmerer is determined to do whatever necessary to keep them from going the way of Cornell's.
Kemmerer is only the latest in a long line of Princeton horticulturists whose living monuments stand everywhere around us. But perhaps none is more responsible for the beauty of today's campus than James Clark, who directed the university's landscaping efforts from 1928-62. Born in Scotland, Clark received his apprenticeship in the gardens of Cathes Castles. On his retirement, the Horticultural Society of New York presented him with its distinguished service award as "one of that breed of Scottish gardeners that knows no peer." It was Clark who planted many of the rare and unusual trees in the gardens of Prospect, until 1968 the president's home.
Clark now lives in retirement near Lake Carnegie, in walking distance to many of the willows and oaks he planted along its banks. He regards his trees in much the same way as a professor might view prize pupils who have gone on to great things, and when talking of Prospect he notes with pride that the "entire second generation" of trees there were planted by him. These include a giant sequoia, a Spanish fir, a tiger tail spruce, a Himalayan pine, a blue Atlas cedar ... and the dawn redwood.
A short, spry, tweedy man with a neatly trimmed moustache and a burr in his voice, Clark took the writer on a tour of Prospect last month. Our final stop was at the dawn redwood, which towers 70 feet over the rhododendrons to the right of the driveway -- a naked skeleton in March, for it is one of those rare "evergreens" that loses its needles in winter. Clark had last visited the tree about a year ago, and he seemed as amazed as a schoolboy as he circled the great gnarled trunk. It looked in fine shape, he said, although squirrels had obviously been at the flaking red bark.
When Clark planted the dawn redwood in 1948, it was only six feet high and barely as big around as a man's arm. He had nurtured it from one of 150 seeds he obtained from the Arnold Arboretum in Cambridge, Massachusetts, which made them available to colleges and universities after a special expedition brought them back from China after World War II. Before 1942, when the dawn redwood was discovered growing halfway up the Yangtse River, this species had been known only from fossil specimens and was thought extinct. The seeds, which Clark germinated himself, sprouted "like hair on a dog's back," he recalls. He planted other seedlings in a grove by the lake, at the old nursery down from Poe Field, and near the PJ&B station. The rest he gave away to fellow horticulturists up and down the East Coast. Clark's "fossil trees" are growing today from New England to the southern states. With care they will live a thousand years.
Like the architecture it complements, Princeton's landscaping is eclectic -- a seemingly casual mix of imported and native trees, hardwoods and evergreens that, taken together, invariably leaves an impression. And as a member of the American Horticultural Society, which lists many of the university's trees in its computerized records, Princeton attracts horticulture buffs from all over. "While we may not have as many varieties as some arboretums," says Kemmerer, "what we have are large specimens, which is what people are really interested in seeing."
Frederic E. Fox `39, the university's recording secretary and something of a natural resource in his own right, says that when he takes people on a tour of the campus and asks them what distinguishes it most in their eyes, the answer is usually "the trees." "They do give this place a particular charm and style," says Fox, an ordained minister whose Welsh ancestors, Druids all, were tree worshippers themselves. When he served as a speech writer for Dwight D. Eisenhower, Fox convinced his boss to revive the presidential tradition of planting trees around the White House lawn.
It was also Fox's idea that a fitting way for the university to honor his classmate and friend Frederick "Bud" Redpath `39 for his years of service on the Alumni Council would be to plant a red oak along the wall between Stanhope Hall and Maclean House. Carl Breuer `29 planted another red oak near Seventy-nine Hall in honor of the professors who had taught his son, Anthony Breuer `65. Some 12 years ago a group of anonymous alumni set up a special landscaping fund to help perpetuate the verdancy of Princeton's campus. The fund has paid for the planting of many trees and underwrites the annual maintenance on the gardens of Prospect and Laurie House.
Princeton's trees are a living link to its past and future. The pair of sycamores standing on the Maclean House lawn in this Bicentennial year were vigorous saplings when Washington's troops scattered three British regiments at the Battle of Princeton. Chances are good that they will still be standing sentry when the nation celebrates its half-millennium in 2276.
Any tree tour of the campus should start on the front lawn of Maclean House (1), home of Princeton's president from 1756 to 1879. Here you will find the so-called "Stamp Act trees," a magnificent pair of sycamores ordered by the trustees in 1765 and probably planted in the spring of 1766. These are the oldest trees on campus, though at 210 years of age they are barely past adolescence -- the sycamore, or "buttonwood" (named for its button-like seed balls), may live to 600 years. Native to lowland areas in the East, it is the most massive of our native trees, and Indians favored its trunk for dugout canoes.
A fine example of American elm** can be found immediately behind Stanhope Hall (2). Identified with Main Streets from Massachusetts to the Dakotas, this tree forms a vase-shaped crown whose drooping branches make a thick canopy to cool the hottest day. While the Dutch elm disease has taken its toll at Princeton, the elm remains the most populous tree on campus, gracing McCosh Walk, the promenade between the chapel and library, and other areas. No Methuselah as a species, it seldom lives past 175 years.
Next to FitzRandolph Gate (3) stands an American Beech, a climax tree of the Eastern forests best known for its smooth gray bark which proves an irresistible attraction for people with pen knives (Daniel Boone's "cilled a bar" inscription was done on a beech ). This specimen probably dates from the mid-19th century. Another fine American beech stands at the east end of McCosh Walk. The towering tree by the beech is a tulip poplar, named for its tulip-like flowers, although in fact it's not a poplar but a member of the magnolia family. This is the tallest deciduous tree on campus -- as well as one of the most handsome -- and it may well date from the 1825 replanting of the lawn in front of Nassau Hall. Another nice example stands in front of Prospect.
The huge white ashes which line Cannon Green (4) were probably planted in 1836, when Joseph Henry laid out the quadrangle. With their five-foot diameters and deeply rutted bark, these are the most imposing trees on campus and among the best examples of the species found in the Northeast. Lumbermen value the hard, tough wood of the white ash for such things as baseball bats and polo mallets. Other giants can be found behind Alexander Hall and up from the PJ&B station.
In the courtyard north of Blair Hall (5) stands the largest London plane tree in New Jersey. In the 17th century horticulturists crossed the American sycamore (one seed ball per stalk) with the oriental plane tree (three balls per stalk) and arrived at the London plane tree (two ball per stalk), which as the name implies is often planted in cities.
Fine old specimens of white pine can be found throughout the campus, but the one on the lawn of the Art Museum (6) has the distinction of being a remnant from the grove of pines that stood here more than a century ago. The white pine, which once grew in majestic stands throughout the Northeast, was long ago devastated by lumbering.
The red oak on the east side of Architecture Building (7) is the largest of its kind on campus and probably two centuries old or more. It is the state tree of New Jersey. Nathan Hale, a Yale man, was hanged from a red oak.
At Prospect (8), one enters a veritable aboretum of exotic species, some dating back to the construction of the house in 1849 and earlier. Along the fence fronting McCosh Walk are several large ginkgoes, a "fossil tree" which grew world-wide 200 million years ago before going into decline and retreating to central China. Thanks to horticulturists, the ginkgo has enjoyed a second coming and has proved surprisingly hardy, seemingly immune to attacks by insects or disease (one theory to explain this: the ginkgo has simply outlived its natural enemies). It also tolerates air pollution.
The gray-barked trees closer to the house are European beech. Along the driveway near the front entrance (9) are another tulip tree, an Eastern (or Canada) hemlock, and a blue Atlas cedar from the Atlas Mountains of North Africa. On the west side of the driveway, towering above the rhododendrons, is the dawn redwood (10), another "fossil tree" thought extinct until its discovery in China some 35 years ago.
Along the west side of the house (11) stands an English yew, probably planted as part of the original landscaping in 1849. An evergreen long regarded as a "tree of life" and associated with cemeteries in Europe, yews have reportedly lived 1,500 years. Like holly, they are either male or female, and only the latter produce berries. The bark, leaves, and berries of the yew are poisonous, and ancient writers warned against sleeping under them.
The cedar of Lebanon just down from the yew may be the best specimen of its kind in the United States. This is the cedar of the Bible, vast numbers of which once grew in the Near East before lumbering reduced them to a remnant, that only about 300 remain in Lebanon today. They may live 2,500 years. A smaller cedar of Lebanon stands immediately to the west, planted by James Clark about 30 years ago. Clark is also responsible for most of the other evergreens in this section of Prospect garden, including a Himalayan fir, Spanish fir, tiger-tail spruce and giant sequoia, many of which have identifying plaques.
Leaving the garden on the path toward Brown Hall, one notices the ground covered with the twisted seed pods of the honey locust, a tree armed with spikes running along the trunk and branches. The gummy substance inside the pods tastes sweet.
Other trees of interest include a find copper beech just to the west of Jones Hall (12); and espaliered magnolias on the west wall of Pyne Hall (13), put in by Mrs. Beatrix Farrand, the university's consulting landscape gardener in the 1920's. Further south (not shown on our map), one finds red, sugar and Norway maples along Wilcox Walk; hardy rubber trees in front of the MacMillan Building (pull the leaves apart and see the latex spread); and, down along Lake Carnegie, many yellow willows, including a specimen near Broadmead Street that is the largest in New Jersey. -- J.M.
The Princeton campus might be viewed as a vast arboretum -- a carefully planned tree garden that, with its mix of exotic imports and native species, would never be duplicated in nature. But on the edges of the campus and beyond, one can find patches of woodland not unlike the primeval forest which stood before Princeton was settled in the 1690's. These areas, particular the 500-acre woods of the nearby Institute for Advanced Study, are the domain of Henry Horn.
An associate professor biology whose innovative work on the theory of forest succession has gained him a national reputation, Horn prefers nature in a wild rather than a cultivated state. "My thing is natural trees more than the exotics," he says. His early fieldwork at the Institute woods led to a book published by the Princeton University Press, The Adaptive Geometry of Trees, outlining a novel theory that links a tree's role in forest succession (the process by which one species succeeds another as a forest ages) to how its leaves are arranged on the branches."
When introducing students to the fundamentals of forest ecology, Horn often takes them to the stretch of woods on the bluffs along Washington Road, just north of Lake Carnegie, where the two of us went one day this winter. We stopped at a hefty red oak, and Horn assembled a stainless steel device which looked like a large T-wrench. He held the instrument -- a borer to collect tree-ring samples -- against the trunk. Leaning his weight into it, he turned the borer like a corkscrew, which squeaked as it penetrated the tree. After a minute he removed a glistening wet cylinder, five inches long and a quarter-inch in diameter, the darker heartwood at one end phasing into lighter new wood and the reddish bark. The wood's large vessels -- a characteristic of oaks, Horn explained -- were clearly visible in a series of bands separated by the annual growth rings which told how the tree had fared since about 1943.
"This one's in very good shape -- it's grown well for the last three years," he said. The rings from the middle years were noticeably smaller, indicating poor growth, while the oldest rings broadened out like an accordion, showing the tree had passed through a particularly robust periods until a decline set in about 1955. (It may be only a coincidence that the tree has perked up again since Princeton began to admit women, yet Horn keeps a "big chunk" of an old tree from some nearby woods whose growth rings he has correlated to major events in university history. "It shows some very interesting responses in terms of growth to things like coeducation," claims the biologist, whose sense of humor is at least as keen as his scientific acumen.)
As we walked along, Horn pointed out other indicators of the forest history. Across Washington Road, many of the bigger trees sprouted large limbs close to the ground, indicating they had probably grown up in an open area which encouraged the branches to reach out, rather than up, for light. We paused beside an uprooted tree. "When a tree goes over it tends to lift dirt out of a hole behind it," said Horn. "This mound and hollow configuration can persist for a long time -- studies have been done in New England where they've been traced back to the 1600's -- and from them a trained eye can often tell if a wood is an overgrown field or if it's been a forest from the beginning. Afield would have been plowed smooth, with no mounds and hollows. This plays a role in succession, too. When a tree goes over it forms a natural environment which certain species adapt to. The black birch, for instance, which prefers well-drained soils, will often colonize the mound, while the red maple will colonize the hollow, which is wetter."
Near the top of the hill overlooking Faculty Road we came to a stand of ashes. "I suspect this area was cleared all at once," said Horn. "both ash and tulip trees under natural circumstances grow in small or medium-sized openings. Yet unlike the tulip tree, the ash can get going in the shaded understory and wait for a blowdown of the bigger, older trees before it takes over. If no opening develops in 15 or 20 years, the tree dies. The tulip can't get along in deep shade at all, but it has widely dispersed seeds which can colonize an area at some distance away. Ash invades the understory and waits for openings, while tulip invades openings directly."
Horn has a feeling for trees which goes beyond his interest in them as a scientist. When telling the novice how to distinguish one species from another at a glance, for instance, he may describe the "nice, flaky bark" of the white oak. He can also stand in a grove of evergreens with his eyes closed and , in most cases, identify the species by the sound made by the wind through the branches. The poet's line about "the murmuring pines and hemlocks" almost certainly refers to the white pine with its long, delicate needles, he says. But his interest in ecology also encompasses birds as a graduate student he study adaptive colonial nesting in Brewer's blackbirds) and butterflies (at his summer farm near Lake Champlain he is looking into lepidopteran social systems). How was Horn turned on to nature?
"If you want to blame on something in particular," said the 34-year-old associate professor, "my father was a Lutheran minister who had wanted to be a forester. I had nine brothers and sisters, and he would take us out on field trips and encourage each of us to specialize in something -trees, birds, or whatever- and learn all that we could about them. We finally got to the point where we began telling him things. My mother was always teaching us to ask questions. She introduced us to the scientific method without knowing it -or maybe she did know it.
Horn lived in Virginia and Georgia, spent his summers near Ithaca, New York, and finally moved to Cambridge, where he went to high school and the Harvard. He felt trapped in the city but taught nature studies at a summer camp. At Harvard he majored in biology and learned the discipline that would shape his life. "In 1961 or '62 I heard about ecology, and a light went on my skull that told me I could make a living forever as a Boy Scout nature counselor." -JM
Princeton Alumni Weekly April 19, 1976