Like the forecasts for the weather conditions that influence the changing autumn leaves, predictions regarding the quality of Ohio’s fall color, while based on science, are not infallible.
Predictions about the brilliance and longevity of Ohio’s fall foliage are often based on variables such as sunlight, temperature, rainfall and wind. Bright sunny September days and cool nights tend to make red, orange and bronze leaves more vivid.
Early frosts often cause trees to prematurely build an abscission layer, a barrier that builds up between the leaves and branches and prevents carbohydrates and water from passing in and out of leaves, thus turning leaves “ahead of schedule.” Dry conditions can cause a delay in leaf color change and windstorms can quickly bring leaves down, ending Ohio’s fall foliage season abruptly.
The seasonal leaf change phenomenon takes place every year and is easy to predict. Each October, leaves throughout Ohio turn colors and drop from trees. The transformation, which occurs earlier in northern Ohio than in the southern part of the state, is caused by a decreasing amount of daylight as the season changes. As a result, the formation of the abscission layer causes green chlorophyll to break down so that colors like gold, yellow, brown and orange show through – especially in hickory, birch and beech trees.
At the same time, the leaves of many “sugary” trees such as maples, dogwoods and sweetgums undergo a chemical change triggered by the cool nights and sunny days that are characteristic of mid-to-late September. The chemical change results in deep russet, purple and bronze shades.
The Ohio Department of Natural Resources has issued the following official fall foliage forecast:
The drought and heat through part of July and all of August has stressed the trees so that they will begin to show their fall color in mid to late September. This will be noticed most in urban areas, where trees live a tougher life. Otherwise, we will keep our fingers crossed that we get rain again in September and the temperatures start cooling off in the evenings. If the weather in September cooperates, we should be on track for northern Ohio peaking in the first and second week of October, central Ohio peaking around second and third weeks, and then southern Ohio peaking through the fourth week.
Ohio Fall Foliage Resources:
To help Ohioans plan seasonal outings and enjoy the fall color that will radiate through Ohio’s 100 plus tree species, ODNR will post weekly fall color updates at http://www.dnr.state.oh.us/tabid/9584/default.aspx. The reports will begin September 22 and run through the first week on November.
The ODNR web site will serve as a premier guide to Ohio’s fall color season. Its pages provide information for travelers who want to map a scenic road trip, adventurers who are refreshed and energized by the cool autumn weather, vacationers who seek places of solace to enjoy the changing seasons and even the students who need a resource for leaf collection projects.
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