As the weather cools, our thoughts turn to football and baseball, sweaters and falling leaves. But why do trees lose their leaves? Why do they turn such brilliant colors? Listen to this week’s episode of Trees Are Key to find out.

Our Species Spotlight this week is Ulmus Americana — American elm. This poor tree has faced a dreadful enemy, the Dutch elm disease, but that is no reason to give up on it. Find out more about our stately American elm by listening to this week’s episode.