Below is a snippet from Kathy's #Mailbag, from August 19th, 2022, published in the News-Gazette regarding the foliage on the University's main quad. Brent Lewis and Ryan Welch of UI Facilities and Services were featured and shared information on the history and approach to plantings on campus. 

The article can also be found at: https://www.news-gazette.com/toms-mailbag/kathys-mailbag-aug-19-2022/article_ae9f4d54-6f93-5a24-8551-e533204bf577.html

Younger trees on the UI Quad

"As I walked through the University of Illinois’ Main Quad recently, I noticed that most of the trees did not seem as old as I would expect. What is the history of the trees on the quad? Have there always been trees there? When were the current batch of trees planted?"

A short history, courtesy of grounds superintendent Ryan Welch and landscape architect Brent Lewis, both with UI Facilities & Services:

In 1929, the Board of Trustees took the advice of renowned landscape architect Ferruccio Vitale, who warned that planting a wide variety of trees on the Quad “would tend to minimize the impressiveness and the serenity of the planting design.”

Elm trees were a traditional choice that did well in local conditions. “No tree is more majestic nor better adapted in form and in scale to form the setting of the University's new buildings,” Vitale said. So the walkways on the Quad were lined with elms sometime around 1930. Over the years, they were lost to Dutch elm disease and phloem necrosis (elm yellows). The last elm trees were removed in 1956. 

The elms were replaced with thornless honey locusts. This tree was selected for its large mature size; light, dappled shade produced by the lacy foliage; tolerance to a wide range of soil conditions and drought; and yellow fall color. Only six honey locusts remain on the main quad from the 1956 planting.

A variety of native oak trees replaced trees that were removed. Most of the recent plantings include chinquapin, swamp white and bur oak.

The university’s current strategy is to diversify the tree plantings with native species and avoid overplanting any one type of tree. Welch and Lewis note that the current diversity of plantings on campus is “very high and is on par with most arboretums.”

Diversifying the campus’ tree inventory turned out to be a wise decision. Between 2015 and 2020, more than 500 of the UI’s ash trees – about 3% of the campus’ tree inventory – were removed due to the damage caused and risk posed by the emerald ash borer. The wide variety of trees on campus meant that the loss of even 500 ash trees did not leave large swaths of the campus looking barren.

Plant geeks may view the campus’ tree plan and get to the tree inventory database at http://go.fs.illinois.edu/tree.