Sedum Rock plants
I want to know how to kill them off.
Remove small infestations manually by digging up the roots.
For larger infestations you will likely need to use a herbicide that contains 2 4-D.
Follow all packaging directions.
If you use a herbicide that contains glyphoste, it will kill everything around it, as it is not a selective herbicide.
You may need to add a surfactant to the soluction. A surfactant is recommended for killing weeds with a shiny or waxy surface.
Repeat the application in a week if the plants still appear green.