Trees give us beautiful colors in the autumn season, but there are many common misconceptions about this wonderful fall event. As we head into the Peak Fall Foliage Week here in southern Wisconsin, our team of certified arborists sets out to bust some of these myths and let you in on the amazing secrets of fall color.
Myth #1: Yellow leaf color in autumn is caused by the chlorophyll changing color in the leaves as it breaks down.
FACT: Chlorophyll is actually a green pigment in the leaves. When trees stop producing chlorophyll in the fall, the pigment stops filling the leaves, so their natural yellow color is revealed. Fun fact: Yellow leaves have lots of carotenoids - the same pigment that makes some vegetables orange and egg yolks yellow.
Myth #2: Yellow and red leaf color in autumn is caused by the same biological process in trees.
FACT: Yes and no! Trees with leaves that turn red do stop producing chlorophyll, but the red color is caused by production of anthocyanin by trees in the fall. Anthocyanin is a toxic, reddish-purplish pigment that helps trees protect themselves from insect pests over the winter.
Myth #3: Frost is what triggers the autumn color change.
FACT: Frost actually halts it. The declining amount of sunlight each day in the fall is the main trigger of color change. In addition, warm fall temperatures can delay the end of chlorophyll production and leaf color change. Here’s an interesting fact: Trees start their color change in late June after the summer solstice, when the minutes of sunlight start to decline. It’s a slow process at the start.
Myth #4: You have to travel to see the best fall color show.
FACT: This is actually true if you live anywhere but the Midwest! The Great Lakes states are predicted to have a banner year for fall color in 2021.
#Myth 5: Predicting fall colors is a guessing game.
FACT: This is less and less true. SmokyMountains.com’s national, interactive fall foliage map integrates nearly a decade of data and predictive analytics, which allows its statistical experts to get closer and closer to 100% accuracy. It’s a neat, simple-to-use tool for seeing when fall colors are expected to peak in every state. Check it out at https://smokymountains.com/fall-foliage-map/.