ParkTalk Podcast

S31 Episode 01: Fall Colors

Ed Hedborn, manager of plant records at the Morton Arboretum and author of the Arboretum's Fall Color Report, explains some of the factors behind the timing and variations in color of our fall foliage.

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Guest, Ed Hedborn, and Host, Sue Omanson

Quotes from the episode:

“Different trees have the ability to change to different shades of color depending on the conditions they are growing in and the weather they experience. Last year (2021) in the summer, you had hot, dry (conditions) and not much rain in the fall; that doesn't allow the tree to make vibrant colors. They are stressed, so they show it with lighter, more faded colors. When the plant has optimal conditions, more moisture, then the colors can pop. You get the brightest colors when you have bright, sunny days, cool nights and when the plant has adequate moisture. If you have warm nights, that can hold off the color change. Ultimately, what really triggers the color change is decreasing day length, which doesn't really change from year to year.” – Ed Hedborn

“The most common yellow tree in home landscapes, if it's a fine, small-textured leaf, would be a honey locust. Other yellow trees are hackberry and gingko—which will turn a gorgeous, even yellow color. The standing joke (about gingkos) is that you have a frost and (suddenly) there is a ring of yellow leaves around the base of a bare tree, because they almost all drop overnight. Other yellows could be sugar maple (depending on the year) and hickories. The oranges—the classic, royalty of fall color—is the sugar maple. The autumn blaze maple is a hybrid, a cross between our native red maple and the silver maple. When you cross the two, you get the red fall color from the red maple with the ability to grow in alkaline soils from the silver maple.” - Ed Hedborn


A sugar maple on Jefferson St. in Naperville, near the Riverwalk entrance  

Autumn blaze maples (Freemans maples) at Centennial Beach

Additional notes:
  • Please note that callery pear trees, including Bradford pear trees, are invasive. Birds pick up their small fruits and spread them into woodlands and along roadsides, where they crowd out more diverse trees and shrubs. Therefore, they are not recommended for planting.
  • Leaves will change color at different rates depending on their exposure to sunlight. For example, the top of a tree and the south facing side will turn first.

A honey locust tree in downtown Naperville  

Fall Color Report

View the reports here. Ed Hedborn writes these weekly reports in autumn for The Morton Arboretum.

Where to see fall colors
  • In Naperville, visit wooded areas at Knoch Knolls Park, Seager Park, the Riverwalk, along the DuPage River Trail, and in forest preserves in both DuPage and Will County.
  • Visit The Morton Arboretum to see trees from around the world, with the most variation in color and species.

A white ash tree along the Riverwalk

Learn more about the trees mentioned in this episode

Information and pictures in the links below are from The Morton Arboretum. You can search other trees here.