Why Leaves Change Color?
Scientists don't yet fully understand all of the complicated actions and interactions that produce the
spectacular displays of autumn leaf colors that are a highlight of the fall months. Although not fully
understood, several factors affect when and how leaves change color and the hues they produce. These factors include:
- Shortening of day length
- Cooling temperatures
- organic pigments in the leaf cells
- sunlight intensity
- tree genetic traits
- site characteristics
Why are fall trees more intense some years?
Cool Night Temperatures - An extended period of cool night time temperatures below 45 degrees but above freezing helps to develop
more anthocyanins in the leaves bringing out more intense fall colors in trees.
- Sunny Days - Bright sun filled days allow the leaves to trap the sugars from the dwindling chlorophyll creating fantastic fall color.
- Calm Days - Stormy and windy days help to release the leaves on the trees. An extended period of calm days help to enhance the viewing time of fall foliage.