If a tree exhibits visible symptoms of a disease late in the season, what should be the first response?

Investigating potential causes is the appropriate first response when a tree shows visible symptoms of a disease late in the season. This approach allows for a thorough understanding of the issue at hand. By identifying the specific disease or stressor affecting the tree, an appropriate management strategy can be developed, rather than jumping to drastic measures like removal or treatment.

Removing the tree immediately could lead to unnecessary loss, especially if the symptoms are indicative of a treatable condition. Applying fertilizers might address growth but would not address the underlying issue causing the disease symptoms. Feeding beneficial insects might provide some level of biological control, but without understanding the root cause of the symptoms, this action could be misguided and ineffective. Thus, taking the time to investigate potential causes ensures a more informed and effective response to the tree's health issues.