I agree that when first planted it is best to not put them too deep. But I have noticed here that once they are settle they do seem to pull themselves down and/or new fans are deeper. I leave them alone now otherwise I would be digging up plants every year. But for a couple of years I was worried about it and tried to go around and raise them all up. It really seemed to make no differnce , at least not here where I am which is zone 5b.