Combining xeriscape and lawn irrigation
I'm having mulch and xeric plants installed next to my lawn (removing over-eager junipers) and 2 landscapers have told me they'd extend the current sprinkler system with drip irrigation. I think I need two entirely separate systems, since starting the new plants and maintaining the old lawn require quite different watering schedules. However, running separate lines under the lawn over to the xeric areas will be disruptive and expensive.
What other solutions are there?
You are correct in that drip should operate on a separate zone. To avoid the hassle and expense of installing another valve - assuming your control clock is not "maxxed out" on stations - and running a line across the lawn to your new drip system, consider this idea.
If your mainline for the lawn irrigation system run near (or, even better, under) your new bed, your irrigation guy could tap into the mainline to allow installation of a line with a timer (battery operated) to run the drip system in your new bed. It would be a timer like those sold to attach to an outdoor spigot.
I have done this at my own house to avoid the installation of underground pipe and additional valves and wiring.