Question
I have lived in my house for 26 years.  I have been fighting an unwinnable battle with a grass that produces rhizomes and overcomes my mulched plant beds.  I have had whole areas of lawn repaced by sod, and other areas reseeded, but this grass continues to invade unwanted areas.  At one time, I found a product that worked if I sprayed around the beds, but I did not keep the container and the products I am using now are not working.  How can I kill it in specific areas like my mulched beds?  I do not want to attempt to kill it in my lawn.  I have been told that I cannot.  I just want to keep it out of my mulched areas.
Thanks so much for considering my question.
Magdalene

Answer
Taking out a grass weed from an area which is not under grass is comparatively easy. You can use a product containing fluazifop. "Fusilade" is a brand name product. It kills true grasses so keep it off the lawn.
You can also use glyphosate ("Roundup") but you must keep it off ANY desirable plant.