I live in south central Louisiana & strive to raise oak trees for shade.  This year, there has been an influx of Buck moth caterpillars, learned what they're called from Google & that they favor eating leaves & stems from these oak trees, but not to worry because the leaves will return, which they do.  

However, there are so many, I decided to spray what I thought was a "light" insecticide on the tree limbs. But to my demise, I realized what I mistakenly sprayed ended up being a pretty strong herbicide.  Shortly after spraying this the grass below the trees was dying & also the tree limbs that I had sprayed.  Google recommended excess watering of the trees as an attempt to flush out any herbicide that was transmitted to the root system.

Any suggestions and do you think that the trees may survive.