I was reading an older book recently and the author mentioned in passing about planting grasses (fountain, etc.) near fruit trees.  He didn't go into any detail but wrote kind of "matter of fact" that it was a bad idea. 

I am in South Florida (zone 10) and my wife loves grasses.  Are there any reasons to not plant grasses near my fruit trees.  Are grasses considered anti-companion? 

Thanks in advance.