Weather Tidbits: Weather’s Impact on Fall Foliage

We’ll be discussing the weather’s impact on fall foliage in this edition of Weather Tidbits. The loss of daylight is the number one cause of color change, though the weather has a secondary effect in terms of how the fall foliage will evolve through the season. The two main secondary factors are soil moisture and temperature anomalies or trends. If the soil moisture is dry, it causes extra stress on the trees. When a tree is drought stressed, it has to use as little resources as possible as a survival mechanism. So, the tree might as well go dormant early if it is under drought stress. High soil moisture will promote late leaf change. Very cold temperatures will promote early leaf change, while mainly warmer than normal temperatures will cause the leaves to change later.