I did this a few years ago. I was fortunate in that the original
installer had had the foresight to build a manifold that had capacity to
add two control valves, so I just added the valves (be certain that you
get the type that can be adjusted to reduce the water pressure; drip
systems use low pressure) and ran some lines down my flower beds. I
installed the drip nozzles, and some misters, with a kit.

I didn't have this problem, as my beds are all along the perimeter, but
if you will have some in the interior of the lawn, you will have to find
out where the original lines run, and avoid them when you are trenching.
Fortunately for me, our excellent original installer had left a map
showing where he ran the lines.

Sandye wrote:
Hi...I'm new to your group..Recent retiree transplant from Oregon to SW
Washington...Have a large lot that is primarily in lawn with perimeter
straight edged beds...want to work toward more island flower beds and
sculpting the existing beds...also have a large collection of large
container plantings that are currently serving as my "holding beds"..

There is an existing underground sprinkler serving the lawn and 80% of
the beds, that is approx 6-7 years old...want to augment that with
automatic drip system for containers and new beds....

Have any of you some experience or war stories you could share....would
really apprecicate it....Am looking for hints as to making the system
as easy to maintain as possible...Thanks a bunch