COLUMBIA, Mo. – Fall color is kind of like Christmas morning, says University of Missouri Extension horticulturist David Trinklein. “You don’t know if you are going to get an orange or a lump of coal in your stocking.” 

Some years are better than others, he says, and about once a decade, colors really pop. “Unfortunately, because of the recent warm weather that followed a rather dry late summer, it does not appear as if 2021 will be one of those years,” he says. 

“Leaves of many species that turn early are simply drying without changing color, but the heavy hitters of fall foliage have yet to come to bat,” he adds.

Missouri’s size and diverse landscape make it possible to follow the color from one part of the state to the other. Color changes begin in northern Missouri and move south. Leaves of different deciduous woody plant species turn colors at different times. As a result, fall color in most parts of Missouri lasts from four to six weeks.

Sugar maples are the best bets for colorful fall foliage. They burst with yellows, golds and reds along limestone bluffs bordering the Missouri River. Other species, such as hickories, yellow poplar and persimmon, light up the landscape with their lush yellows and golds. Not to be left out of the show, oaks add rustic reddish-browns for contrast.

Of course, the changing of leaves is not just for show. Leaf shedding is part of the dormancy process that helps trees survive winter, Trinklein says.

During the spring and summer, leaves make food for the trees. Chlorophyll absorbs sunlight to transform carbon dioxide and water into carbohydrates such as sugars and starches through photosynthesis.

The shorter days of late summer trigger the dormancy process. A layer of cells called an “abscission layer” forms at the point where the leaf stem attaches to a branch or twig. Sugars, blocked from exiting the leaf, turn into colorful pigments known as anthocyanins, which usually are red or purple.

In addition, chlorophyll starts to break down. That is when yellow and gold pigments called carotenoids get to shine. These pigments are present throughout the growing season but are masked by chlorophyll’s dark green color.

Leaf color intensity depends on temperature, light and the availability of water throughout the year. Color-watchers favor a steady supply of mild, sunny days and cool but not freezing nights for the best chance of fall brilliance. Leaves also need some moisture for colors to intensify.

Contrary to common belief, frost is not necessary for trees to begin their color show, Trinklein says. Early frosts may even tarnish leaf color.

“Whatever the outcome, fall leaf colors are a treat we are privileged to witness only once each year,” Trinklein says. “Therefore, take time to enjoy them.”

Visit the Missouri Department of Conservation’s regional fall colors reports at https://mdc.mo.gov/trees-plants/fall-color.

Photos available for this release:

https://extension.missouri.edu/media/wysiwyg/Extensiondata/NewsAdmin/Photos/stock/plants/amur.maple.jpg
Amur maple. Photo by David Trinklein.

https://extension.missouri.edu/media/wysiwyg/Extensiondata/NewsAdmin/Photos/stock/plants/oaks.jpg
Oaks. Photo by David Trinklein.

https://extension.missouri.edu/media/wysiwyg/Extensiondata/NewsAdmin/Photos/stock/plants/sweet.gum.jpg
Sweet gum. Photo by David Trinklein.