Just a side story on chemical application. In my area we have blackberries and alder considered invasive. Spraying blackberries, or any ryzome type plant in the summer is wasting chemicals. The best time is fall when the berries start to shrivel. The plant is sucking sugars back to the ryzome for winter dormancy and if you spray then you kill the root. 2 nd best time is in the spring when new leaves are starting. and third is as you are cutting if in the summer, and I mean applying within a couple of minutes of the cut. Also be prepared to reapply for many years...