Does anyone have a recipe for killing a standing tree, a sycamore , so that leaves will not be a problem? A number of years ago I killed an Ash tree by drilling holes(6) around the trunk in mid summer, filling the holes with Roundup, the leaves droppd very shortly afterwards (days), this time I am using Gallup which is supposed to be as good as Roundup, and no sign of a dead tree yet. I have used Roundup since the Ash tree and I thought it wasn't as good as the original experience, so maybe something is missing in these chemicals.