Question
How do I kill torpedo grass? I have it in zoysia grass ,azaleas, roses and around crape myrtles.

Answer
Fluazifop is a chemical that will kill true grasses like torpedo grass (Panicum repens) and not harm most other vegetation. A product that I have used which contains fluazifop is "Fusillade II". I am not sure that it is available to homeowners but other formulations may be. Please follow the label.
I have used the scientific name of the weed and the chemical ingredient in order to be quite clear that we are talking about the same things. This is very important because you are looking for a plant killer that you will be applying near to or over the top of your highly prized plants. My experience tells me that you can do this on the plants you have named EXCEPT the zoysia turf because that is a grass also. I may add that I use professional equipment and I measure accurately in order that there must be no over application. I also follow all label instructions.
Allow me to leave a maxim often used in the trade.

 "There is no safe chemical. There are only safe ways of using chemicals".