Looking for a bit of advice. I have a number of sites a do the grounds maintenance for. They have a number of Mountain Ash Trees (Rowan Trees) that have the signs of having Ash Die-back.   But from everything I am reading Mountain Ash Trees (Rowan Trees) can't get Ash Die-back because they are not an Ash Tree.   The Mountain Ash Trees (Rowan Trees) have for most of this year has had leaf die-back on the ends of the branches, The leaves that they do have all l