2 c vinegar, 1T liquid soap, 1Tsalt....will kill anything! DO NOT USE ROUNDUP.
List of plants used in California drought tolerant yard :: OrganizingMadeFun.com
Hostas and Hydrangeas
So what if the lamp post piece of grass was all hostas (or maybe sedum) from sidewalk to porch, and then another symmetrical planting on the other side of your sidewalk to the porch.