This article by Christine Gelley was originally published by The Noble Journal Leader on October 22, 2018.
October is by far my favorite month in Ohio. The crisp cool air, the autumn colors, and an excuse make a hearty pot of chili are just a few of the reasons. In conversations with others who love October, we tend to wind up disappointed with the lack of brilliant autumn colors so far this year.
It is true that the color change we see with deciduous trees this year is drastically different from last year. By the fourth week of October, most of Ohio’s deciduous forests are a warm mix of orange, yellow, red, and purple hues. Here in 2018, we mostly have a dull green color with a little yellow and red. Where is our beloved autumn color?
You may remember from a previous article that the pigment changes in the leaves of deciduous trees are the result of chlorophyll break down. Chlorophyll is the green pigment expressed in the leaves during spring and summer. It absorbs energy from sunlight to fuel the process of sugar production in the plant, which is called photosynthesis.
When day lengths grow shorter and temperatures get cooler, photosynthesis slows, and chlorophyll production dwindles. In the absence of chlorophyll, other pigments are expressed including carotene, xanthophyll, and anthocyanin.
Color changes are most dramatic in years where summer transitions to fall with a series of warm sunny days, followed by crisp (but not freezing) nights. Warm and wet fall weather tends to delay the color change.
The consistent moisture we have had all year and the lack of cool nights in the first two weeks of October are likely the cause of a slow color change. If we get lucky, a series of sunny days, cool nights, and a dry stretch could still trigger some pretty colors before a hard killing frost.
To track the progression of fall foliage changes in Ohio, follow the Ohio Department of Natural Resources Fall Color Reports at http://fallcolor.ohiodnr.gov/.