A sample of Ohio trees that turn red in the fall is this Dogwood between my pond and the house. This poor tree was damaged during pond construction but has now grown to nearly obscuring the view of the pond.

WHY LEAVES CHANGE COLOR—

“The key to Ohio’s vibrant autumn color season is a combination of long, cool nights and short, sunny days in mid to late September” according to the Ohio Department of Natural Resources.

“Decreasing amounts of sunlight in the fall trigger a chemical change in the leaves of hickory, birch and beech trees that causes them to turn various shades of yellow, brown and orange.

These colors, called carotenoids, were present in the leaves all along, but were hidden by green chlorophylls during the spring and summer.

Additional shades of red and purple, called anthocyanin pigments, develop in late summer in the sap cells of tree leaves that are rich in sugar, including maples, oaks, sweetgums and dogwoods.”

In a nutshell, the green, chlorophyll pigments capture energy from the sun and use it to manufacture simple sugars for the tree’s growth during the summer. We learned to call this process photosynthesis.

In the fall, when the days grow short and the nights cool, trees slow their chlorophyll pigment production and the colorful pigments begin to show through the fading green.

Here’s another interesting fact from the folks at ODNR: Leaves that turn red must have lots of bright sunshine. In fact, if you covered a small section of the leaf before it changes color, the part of the leaf without sunlight will turn yellow while the exposed part turns red.

“With more than 100 species of trees in the state, it’s no wonder Ohio’s fall color season is so spectacular.”