Originally Posted by Elf
Try painting 1/2 dozen leaves on each tree with Round Up. Be sure to wear rubber gloves, and paint both side of the leaf.
Also known as a judicious application of Roundup, as I suggested earlier. I put mine in a sprayer contraption - the sprayer apparatus has a teeny squirter part so that you can spray the stuff just where you want it to go without killing everything else nearby.