i have several lawns where there is 2 inches or more of thatch from probably chemlawn type applications. i am now faced with the challenge of educating these customers on why they have insect and disease damage because of their layer of thatch. what are your guys opinions on aerating lawns like this or dethatching? i aerated a few and it looks like it didn't reduce the thatch much. will i be able to dethatch in the spring as long as i do it before the premergent is put down? also, are dethatching machines as annoying and hard to move around as aerators? i've always been toward dethatching seems to do more harm than good, but don't see how to get rid of this excessive thatch without doing it.