15% Fe won't hurt a lawn but that is a LOT of iron to be sure. The rest of the micros help out too but are probably only needed once a year. Not so sure about the MESA though. I've never had good luck with Methylene Urea.(burns and gives huge growth spurt) 51% must be a Lebanon 25-0-5? In the order Hineline lists the applications, however, this is probably a very good program.