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 tree 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.
- 2010 Fall Tree Prediction-See one experts guess on what to expect in 2010