Polk County Conservation

Fall Colors in Iowa

This podcast was produced by Polk County Conservation and funded by Resource Enhancement and Protection Conservation Education program or REAP-CEP.

After a long hot and humid summer, autumn awakens our senses. The sights of brilliant fall colors, the sounds and smell of dry crackling leaves, the warmth of the day and the coolness of the night are all reasons why Iowa is a wonderful place to be during autumn.

Have you ever wondered how and why Iowa’s trees change color? Due to shorter and cooler days during the fall, leaves quit making food for the tree. When this happens, the green chlorophyll inside the leaf breaks down and disappears leaving the yellow and orange colors visible. The yellow and orange pigments are called carotenoids, which are also found in carrots and corn. Carotenoids color the leaves of hardwood trees such as hickory, soft-maple, yellow-poplar, birch, sycamore, cottonwood, and green ash.

The red and purple colors come from a different pigment in the leaf called anthocyanin. This pigment is not found in the leaf during the growing season, but forms in the leaf late in the summer. The richness of the red and purple color depends on the weather conditions and the amount of sugar left in the leaf. Anthocyanins color the leaves of hardwood trees such as red oak and hard-maple.

You don’t have to travel far to view some of these spectacular fall colors. Take a drive to Jester Park in northwestern Polk County to observe a sampling of fall colors. Yellow Banks Park in southeastern Polk County also offers some wonderful views. The bluffs overlooking the Des Moines River valley are loaded with yellows, oranges, browns, and reds.

It’s hard to predict when fall colors will peak, but in general the northern half of Iowa has prime colors during the last week in September to the second week in October. The southern half of the state has prime fall colors during the second to the fourth weeks in October. Visit www.iowadnr.gov for a current report on fall colors.

This podcast was funded by REAP-CEP which is a program the State of Iowa invests in to enhance and protect the state's natural and cultural resources. REAP provides money for projects through state agency budgets or in the form of grants. For more information about REAP, visit www.iowareap.com.

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