IZZY
If your mix is stronger than the recomended dosage all you will succeed in doing is burning off the leaves before it has time to perculate down to the roots that is why the companies have spent a fortune and many year working out the optimum dose. I spray bindweed it takes about a fortnight to keel over and I have no regrowth using the right strength mix.
MANDY
Deep Root works on Marestail, keep a spray handy and give a squirt to any that shows its face.