There was a bed of irises planted at the base of this tree, however because of poison ivy and a tree stump trying to grow you could not see the flowers. I bought some brush and vine killer and was extremely careful to not get it onto the dogwood trunk or roots that skim the top of the soil in places. I brushed it onto the ivy and the stump branches with a foam brush. It stopped the stump from growing but i have noticed that half of my gorgeous dogwood looks like it is dying. Could the brush and vine killer have done this or is it simply that my tree is dying? I have attached pictures of the brush and vine killer i used, the stump i painted it on at the base of the tree and a picture of my dogwood. The left side is the affected side of the tree. Thank you for any help.