Question: My Arizona ash tree is thin and appears very weak. What causes that, and can it be saved?
Answer: Borers are the most common threat to Arizona ashes, especially young trees. They’ll tunnel through the trunk leaving rather large holes filled with wood pulp. Look closely for signs of their presence. You may be able to insert a flexible wire into the tunnels to eradicate existing worms. Spraying on 6-week intervals during the summer will help prevent additional invasion. Arizona ashes are also vulnerable to late freezes in the spring. Once they begin to leaf out and grow in early spring they seem to be severely harmed by temperatures in the 20s.