We know fall is in full swing when we can smell those apple cider donuts, see the carved pumpkins on doorsteps, and watch the leaves on the trees change color. But have you ever wondered where those beautiful autumnal hues come from?
Check out the start of the leaves changing color from our Edvotek work window this fall!
Leaves are able to display these colors due to pigments. A few of the major pigments found in leaves are: chlorophyll, xanthophylls, carotenoids, and anthocyanins. These pigments produce green, yellow, orange, and red colors respectively. When temperatures are warm, mainly in the spring and summer, leaves produce an abundance of chlorophyll. This pigment is produced to aid in photosynthesis, where the energy from sunlight is absorbed and used to make chemical energy to maintain life in plants, or leaves. The constant sunlight throughout the spring and summer means leaves are constantly producing chlorophyll. So, changes in sunlight exposure triggers leaves to change the amount of chlorophyll that is produced. As fall rolls around, less sunlight hours are available, and leaves respond by gradually stopping the production of chlorophyll. This is when we see fall foliage in full bloom! We see those beautiful reds, oranges, and yellows. Leaves are always producing the xanthophyll, carotenoid and anthocyanin pigments, but in the warmer months so much chlorophyll is needed and produced that the green pigment masks the red, orange, and yellow pigments. The timeline of fall foliage depends on the year. The faster the weather gets colder, the faster the leaves change color as they prepare for the winter months. As the temperature keeps dropping throughout the fall season, the leaves start to fall off the trees as winter approaches1.
The same way leaves change color from green to those warm fall colors is why pumpkins have that notable rich orange hue during the fall months. While pumpkins are growing in the spring and summer they are not orange, but green. In order to grow big and healthy they need to produce large amounts of chlorophyll, and in turn, they give off that bright green pigment. As fall approaches, and temperatures start to drop, chlorophyll production stops and other pigments are able to shine through the degrading green. This is when we see the orange and yellow pumpkins that we know and love2!
Check out some other blog posts about fall that we have!