Fall Foliage Color … Where Did It Go?
December 11, 2014
When September rolled around, we thought “This year, we’re going to have some amazing fall color!” Due to the extra rainfall we received during summer, the early cool nights in September combined with sunny days, fall tree color was on track to be fantastic. But just as the color started to turn up the volume, much of it was stopped dead in it’s tracks. Why did this happen?
Why do leaves change color?
First, let’s talk about how leaves change their color. All leaf cells contain chlorophyll and carotenoids, which are pigments used in photosynthesis. Chlorophyll gives leaves their green color, while carotenoids offer shades of yellow and orange. As the daylight hours become shorter, a layer of cells called the abscission layer blocks the chlorophyll from getting from the stem to the leaves. With less chlorophyll in the foliage, the carotenoids begin to show through, making tree leaves appear in shades of yellow and orange. So, what about those red leaves, you ask? They come from other pigments called anthocyanins. Anthocyanins help trees move nutrients from the leaves back into the plant when fall temperatures begin to get cold. It’s the anthocyanins trapped in the leaves that give certain plants their bright red, purple and crimson colors.
Weather Affects Fall color
Drought in Texas greatly affects when trees begin to change color for fall. Summer drought causes the abscission layer to form early causing the leaves to drop before the color change process begins. A dry summer can also delay fall changes for weeks, meaning trees don’t start to change color before the first frost hits. This year however, we had 4.3 inches of rain in August, plus cool nights and sunny days in September. It was the perfect recipe for a beautiful fall color show. So what happened? A surprise early freeze in November caused many leaves to die before, or just as, they were starting to change color. You may notice many trees in the area that still have all their leaves, but they are completely brown. We’ve seen many red oaks that are still holding all of their brown, frozen foliage. The trees that didn’t suffer as much freeze damage still managed to put on some nice fall color. If we hadn’t gotten that early hard freeze, we probably would have had one of the most spectacular fall color seasons in years.
Each year we watch the forecast and look forward to the changing of the leaves. Properly watering and maintaining your trees will result in a better color show in fall. Its never too late to begin caring for your trees!
Posted: December 11, 2014