My recollection is that "Sudden needle drop" is a fungus attaching a tree under stress. I have 2 dwarf trees, 1 either side of my main entrance, and I am on my second pair in 5 years. 1 or both catch me out eventually because I don't water often enough; presumably. I have 1 healthy and one not so... at present. At a distance they look Ok but I know 1 is unhealthy.
