SureGuard SC is not labeled for St. Augustine or Zoysia. It is only labeled for dorman Bermudagrass.
The label states you could use Sureguard at least 2 months before you install ornamental plants or after ornamental plants are established. You would need to avoid over-the-top applications so it would just be a directed spray directly to the ground (not on any leaf foliage, stems, etc) You can view the full list of tolerant plants on the label.