The signals are all around us. With football season started and all of the harvest festivals around it’s easy to see that fall is definitely under way and we know that winter is right behind it. Over the last couple of weeks we have been digging into the back of the closet to dig out the sweaters, hats, and flannel shirts to make sure we stay comfortable in the fall and also prepare for the winter.
Like us, the deciduous trees that populate the Northeast are also getting the signals that fall is coming and are making the necessary preparations. The triggers for most seasonal plant activities are temperature and the ratio between hours of sunlight and hours of darkness. This ratio is what drives all kinds of plant processes including Spring emergence, flowering, fruiting and also fall color.
In the fall, trees want to shut down the processes that turn sunlight into sugars (photosynthesis). Photosynthesis is not very efficient with short periods of daylights and cold, cold temperatures and ultimately it’s better for the tree to just go to sleep for the winter. When this time comes, trees release chemicals that start to break down the chlorophyll. What’s left behind is the darker red, purple and yellow pigments. These pigments are called anthycyanins and with all of the green chlorophyll gone it is finally time for them to shine.
