I have a neglected area in my yard where a stand of Johnson Grass has invaded. There are a few older iris there which I am not concerned about so I have sprayed the area with Grass Be Gone, not avoiding the iris. I am curious to see what effect the spray has on the iris. I'll post pictures as I see results. I have used this product on lawn grass growing in clumps of Peony and Summer Phlox before successfully with no harm to the plants. Now I'll see with iris.