‘Get out and look at the leaves’: Holy Cross Provides Unique Fall Foliage Experience

Holy Cross botanist explains why leaves change certain colors, when the peak will reach Worcester and how a dry summer could affect the timing.

As the new academic year begins to establish a rhythm, shorts are soon replaced with sweatpants, the sun sets on The Hill earlier and earlier, and the ivy covering brick buildings trades its pop of green for shades of orange and red.

Beyond those iconic ivy-covered buildings, during the fall the College of the Holy Cross offers a unique perspective for leaf peepers – whether they live in the city or have traveled thousands of miles to see the changing of the leaves. 

Sitting atop one of the highest summits of Worcester’s seven hills, the campus provides unrivaled views of the lush forestry surrounding the city. The College's 174-acre campus is also an arboretum, home to 115 varieties of trees and shrubs, meaning anyone walking around campus likely isn’t far from a tree ditching its greenery for oranges, yellows and reds. 

 The College of the Holy Cross sits on one of Worcester tallest hills, providing unique views when the leaves begin to change color in the fall. (Photo by Michael Ivins/Holy Cross)

A tree with yellow leaves in front of a brick building

Why leaves turn orange and yellow

There are two aspects that prompt leaves to change color, according to Kelly Wolfe-Bellin, senior lecturer in biology at Holy Cross, whose expertise is in ecology, botany and environmental science.

The first aspect is the length of the day, which is fairly consistent from year to year. As the day shortens, chlorophyll breaks down in a tree. With a lack of chlorophyll, which gives the leaves their green color, compounds called carotenoids take center stage and provide the leaves with pops of orange and yellow, Wolfe-Bellin said. 

"The timing of that reveal is pretty fixed by the day length," she noted. "That's going to march on and occur during the same time each year."

Red ivy covering a brick building. Students walking in front of the building

Why leaves turn red and purple

The second aspect involves a compound called anthocyanins. Leaves produce these compounds and are the reason they turn red or purple in the fall. Anthocyanins are directly tied to the weather. 

"If our drought had extended and it had stayed hot, I think it would have pushed the reds later and I think it may have made them more drab," Wolfe-Bellin said.

September rain, mixed with crisp temperatures, should result in eye-catching reds and deep purples this year. 

"I don’t think I've ever seen a bad fall in New England," Wolfe-Bellin said. "The travel websites are, like, 'Yes, it’s going to be a great year.' They are always good years. I'm not sure I'd ever say it's been a disappointing fall."

When to look

Students, faculty and staff have a bit of a cheat sheet standing atop The Hill. The vantage point allows for a view of the north and west, where trees will turn before the leaves change on campus. As the west and north change, Holy Cross and Worcester aren't far behind.

Wolfe-Bellin said peak foliage should occur around fall break, the week of Oct. 10.

But students leaving campus should still have a foliage treat waiting when they return, as trees in the city often turn later. Wolfe-Bellin said that may have to do with the city often housing warmer air, but also the tree composition of Worcester, which has many Norway Maple trees that tend to change color later in fall.

"I tell my students they should get out and look at the leaves at some point," Wolfe-Bellin said. "They live in New England. They may only have four years to be here. They should take advantage of fall."