We had a taste of fall for a few days this week, with temperatures well below average. And that got me thinking, how does our summertime weather impact the vibrant colors that we get in the fall?
Let's start off with the big question: Why do leaves change color in the first place?
As we start losing daylight, photosynthesis slows down. The production of sugars in the leaf relies on the sunlight and longer days to produce chlorophyll, which gives the leaves their green color. When the days get shorter, we start to see other colors in the leaves showing up, like red and yellow.
But the extent and length of time our vibrant fall colors last will depend directly on our temperatures and soil moisture before and during the transformation.
Usually, a period of warm days with plenty of sunshine, along with cool nights, will produce the most vibrant display of colors.
We also must look at soil moisture as a factor. If there is enough rain throughout the summer and the soil is adequately moist, the leaves will produce some gorgeous colors. But if there is a severe summer drought, that can delay the onset of color. And a warm period in early fall could cause the leaves to drop early before they have had a chance to change colors.
Trees that might be stressed or diseased could cause leaves to change color early, too. A few trees in my backyard are exhibiting those symptoms. I have a few tulip poplars (the Kentucky state tree) with leaves turning yellow and falling to the ground.
So, what colors can we expect here in Kentucky? With all the rain we had over the last few months, we are on the right track for some vibrant colors. Now, all we need are warm afternoons with cool nights leading up to our leaves changing colors.
We start to see leaves change color in October in Kentucky. Our peak is usually mid to late October.
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