Are the trees trying to tell us something?
Their leaves are expected to change colors in the Fall, not mid-August. But it’s not your imagination; hues of red, yellow, orange and even brown are evident already throughout northeast Ohio. Why?
According to our neighbors in Pennsylvania, CBS Pittsburgh reports that a record-cold summer has led to this early onset of autumnal color. Pittsburgh is on pace for the 9th coldest summer since record keeping began in 1871, says Meteorologist Dennis Bowman. The dog days of summer simply passed us by; some locals have even turned on their furnace on recent chilly nights.
The Polar Vortex pattern that we experienced in January also caused cold temperatures in July. “There has been a frequency of cold fronts this summer, and the weather for June, July, and August has been substantially below normal,” Bowman said.
Leaves change color normally in early fall in response to shortened amounts of daylight and colder temperatures. The green-colored chlorophyll breaks down, allowing the other chemicals in the leaves to stand out and show off their brighter colors… normally in September and October.
According to Cleveland NewsNet5 Chief Meteorologist Mark Johnson, the color change is not widespread; just a sprinkling of trees showing color. The vast majority of local trees are still green. So the early color change we see is likely due to plant stress. Trees can be weakened by a variety of natural and man-made factors.
Of course, persistent cool temperatures can stop the sugar-making process in the leaves earlier than normal. Excessive moisture can also shut down a tree’s process of photosynthesis. On the other hand, excessive heat and drought can cause trees to go dormant prematurely. The stresses can occur over several seasons or even several years. Insects and disease can also weaken a tree and cause early leaf color. Man-made causes include disturbing the root systems of a tree for construction or landscaping.
Johnson points to environmental stress over the past couple of years as the culprit for our early fall colors. During the summer of 2012, northern Ohio experienced 90 degrees or higher on 28 days. Then last winter, we experienced four separate episodes of temperatures dropping to between -10 and -15 degrees. Many trees suffered bud damage from last winter’s frigid temperatures.
So, tree stress has been common across northern Ohio the last couple of years. But Johnson predicts the majority of local trees will begin to change colors in September, right on cue.