The Heat Is On… But Hopefully Not for Long

Now that we’ve passed the midpoint of summer, we enter the peak of the heat. It always feels to me like a test that we have to endure before the September temperatures (hopefully) break, and I think it’s a time when many of us really begin to long for autumn’s cooler temperatures.

As we lament the end of the warm summer nights, we then begin to think about cozying up to campfires. We look for our sweaters. Maybe we dream of pumpkin spice lattes. As a kid, I dreaded the thought of fall. It only meant back to school for me, and I wanted nothing to do with that. But, later as my tree-climbing career began to develop, I learned to appreciate the relief of the fall temperatures after surviving the humid Richmond summer. I also look forward to and enjoy the bright fall foliage in which tree climbing allows me a front row seat.

For a long time, it never occurred to me why the leaves changed in the fall, only how beautiful it is when they do. I didn’t know that the leaves don’t actually change color but rather show their color after chlorophyll breaks down and the dominant green color… leaves. See what I did there? The vibrant fall “color change” is what is left behind. 

Okay, maybe not entirely. As chlorophyll breaks down, other chemical changes may occur, which produce colors through the development of red anthocyanin pigments. Some combinations can bring on the reddish and purplish fall colors of trees such as dogwoods, while others give trees such as the sugar maple a brilliant orange.

Some trees show only yellow colors. Others, like many oaks, reveal mostly browns. These colors result from the combination of differing amounts of chlorophyll residue and other pigments in the leaf during the fall season.

Temperature and the amount of light and water that’s available have a lot to do with the intensity and duration of fall color. Temperatures that are low but above freezing will favor the development of anthocyanin that will produce bright reds in maples. However, an early freeze will dull the red color. Overcast or rainy days will likely increase the intensity of fall colors. 

So, as the lingering summer months continue to keep us cooking, remember to look forward to the coming of the harvest season’s cooling relief and the beauty that is found in the trees above. Its peak tends to be brief and easy to miss, so try and slow down and take the time to enjoy fall’s grace while it’s here.