"Rox's 4 in 1"

I doubt there is any chemical reaction issues. I would venture to guess it hasn't commercially been done because either is not economically viable to produce and sell or the value proposition isn't there (i.e. the pest control or the fertilizing doesn't work as well when combined).

thanks...maybe 1 in 1 week and then wait a week and the next. Want to get the bug issue controlled before it starts this year. Our neighbor's weeds bring in a host of bugs and powdery mildew.