Glyphosate does travel to and through the root system, so could kill or damage the entire plant. It is a good way to kill unwanted plants or stumps, but it has to transfer through to the root, and means pouring on FRESH cuts. I used to follow the tree crew with a spray bottle when they were removing trees, and cutting an X in the stump gives the chemical more access. I was a licensed applicator for 15 years, so I've had some experience. I still use RoundUp where appropriate , but, like any cure that has been over-used, some of the targets have developed immunity. Add to that, as all chemicals, it has a shelf life, meaning, like old drugs it looses potency after time. Unfortunately, there is no "use by" or "sell by" dates on garden chemicals .Don't get me wrong. I love the stuff, and use it myself, but you need to know what you're doing.