Ivy league, no longer

In an earlier post, I traced the origins of the ivy that grew on the walls of the Van Vleck Observatory for much of its history. However, as you can see by comparing an early photograph of the observatory with the building today (below), the ivy has been removed. Why?


Van Vleck Observatory circa 1930 (in black and white), and today (color). Black and white image courtesy of Special Collections and Archives, Wesleyan University. Current photo by the author.

For decades, architects, scientists, and gardeners have been debating the desirability of allowing vines to grow on building walls.  Some considerations were primarily aesthetic:

“A home should seem to be tied to the ground in such a way that it will appear to rise from it without a sudden and abrupt breaking of the surface.”
N. H. Ellsworth, “Planting the Home Grounds: The Use of Vines,” House Beautiful, Volume 48, July 1920, 200.

“…nothing can be more unsightly than a good building metamorphosised with heavy growths of ivy or other plants.”
Sir Thomas Jackson for Times, quoted in “Creepers on Buildings,” The American Architect Volume 120, December 1921, 14.

But others concerned the material impact the vines had on the buildings.  According to a note in The American Architect and the Architectural Review of December 21, 1921 (below), even then, creeper plants were thought to be damaging to masonry.  (Agreement on this point is far from universal.  A 2010 study by Oxford University scientists concluded that ivy can act as a thermal shield and protect brickwork from intrusive moisture.)


“Creepers on Buildings,” The American Architect and the Architectural Review Volume 120, December 1921, p. 14. Image by Google Books.

From a closer look at the literature, it appears that the precise nature of the building material material determines whether a wall can sustain ivy without damage.  Some ivy plants apparently secrete an enzyme that erodes mortar of the kind found on historic buildings like the Van Vleck Observatory. According to Dave Hall, who maintained the grounds at Wesleyan University for over 30 years, much of the campus’s ivy was removed precisely because it was damaging the mortar.  It appears that the vines came down from the Van Vleck Observatory sometime in the late 1980s or early 1990s.

Incidentally, Wesleyan was not alone.  Many colleges such as Middlebury, Harvard and Yale carried out plans to strip ivy off historic buildings as early as 1982.  Ivy league, no longer!

Van Vleck’s living walls

As I was going over old photos of Van Vleck Observatory, I noticed that the now-bare walls of the building were at one point covered thickly in vines. What is more, it seemed that the presence of ivy was not simply an afterthought, or a decoration to make the building more “academic,” but an important design feature of the observatory itself.


Van Vleck Observatory, circa 1930. Image courtesy of Special Collections and Archives, Wesleyan University.

As the moniker “Ivy League” suggests, ivy has long been associated with college campuses. Planting a commemorative ivy vine at the base of an academic building has been a tradition of each graduating class at Princeton since 1866, and Smith College observes an annual “Ivy Day” at its commencement. Many Wesleyan buildings were formerly cloaked in ivy; the brownstone campus today looks much different than it once did.

But while the reasons for planting ivy may be partly traditional, at the Van Vleck Observatory, these vines were also grown for more practical purposes: to help moderate the temperature of the building itself. Ivy formed a living climate-control system, shading the brownstone exterior in summertime, and preventing the sorts of rapid fluctuations in temperature that might cause errors in measurement.

We can see how these considerations influenced the design of the building from the outset. Henry Bacon, most famous for designing the Lincoln Memorial in Washington, DC, was Wesleyan’s campus architect from 1913 to 1924. He designed Van Vleck with input from Frederick Slocum, the observatory’s first director. In a 1914 letter to Slocum, Bacon suggested the use of ivy to help regulate the temperature of the transit room, ensuring more accurate observations. In this sense, the building itself was a sensitive instrument, and ivy was one means of keeping it cool in the summer and warm in the winter.


A letter from Henry Bacon to Frederick Slocum dated July 23, 1914 in Box 2 of the Henry Bacon Collection. Image courtesy of Special Collections and Archives, Wesleyan University.

Of course, aesthetic considerations were also at play. Bacon’s suggestion was later met with agreement by a member of the Wesleyan faculty who thought ivy would make the observatory “a handsome building.” The faculty member’s delightful comment was quoted by Frederick Slocum in his address at the dedication of Van Vleck Observatory in 1916:

Little bits of plaster,
Little blocks of stone,
Make a handsome building,
When the ivy’s grown.