When several factors combine to cause stress and deaths in a tree species it can be labeled as a “Decline Complex”. This tag has been assigned to several situations in the past twenty years, including Sugar Maple Decline Complex in the eastern United States. Damaging agents such as drought, vascular diseases, advanced age, and internal wood decay combined to cause the death of several thousand Sugar Maples in Pennsylvania, New Jersey, and Maryland. A similar situation appears to be arising in our Ash trees. Over the past sixteen months we have noticed a remarkable number of Ash trees showing tremendous amounts of branch dieback. These same trees have suffered from several years of sustained drought, extremely large seed crops, and two different pathogens, and attacks from the very damaging Ash/Lilac borer. Arborists and university professionals are working together to gather more information in order to form a true diagnosis. In the meantime, we are treating each case symptomatically. In other words, if a tree is being attacked by the borer then we will treat it with insecticide trunk applications. If we find root loss from drought, then we will use deep root watering and supplemental irrigation to make up the difference. If you notice that your Ash trees are struggling, don’t ignore it! Let us know and we can try to help.