With no leaves to block our view, winter allows us to see trunk and branch structure more clearly. Sometimes we see unusual growths, or galls, on tree trunks and branches. Galls are formed by excessive cell division in response to infection or irritation by bacteria, fungi, insects, and sometimes environmental stress. Learn how to prune out galls and more in our article https://bit.ly/3u60ugc
Photo: Black Knot in branch gall