The closer to those sprinkler lines you plant, the higher the chances of two things happening:

1) The roots of the tree will eventually entangle themselves in the line, potentially damaging the sprinkler system.

2) If you ever need to service those sprinkler lines, you will have to perform major root surgery on your tree to access the line.

I prefer to water my landscape plants with an above-the-ground drip-line system. The buried sprinkler lines are for the lawn where, of course, the grass roots are very shallow.

If you don't care about the sprinkler lines, you could go ahead and plant wherever you'd like. If you think you might actually someday -use- the sprinkler lines (or a future property owner might want to use them), I would carefully consider the placement of those trees and/or consider digging up the sprinkler lines and reconfiguring the entire system.

plant or transplant ... the conifers

what type of lines??? ... do you mean supply lines.. or heads ...

most conifers wont need much of any water.. after the second year after transplant.. and many will not appreciate being wetted all the time... leaves vs roots ...

i really need you to straighten out the premise.. before i can answer ... do you have any clue where all the buried stuff is???

usually.. lines run in the lawn ... and in the future.. if you had severe problems you would reroute in the lawn ... not dig up established plants and mess under such ...

but that said.. i really dont see trees.. CAUSING problems with such ... they would take advantage of pre exiting problems... not cause them ... your shovel will be a bigger cause.. lol ...

ken

The supply lines that support the heads for the sprinklers run a grid across aproxamitly 5000 square feet of our lot

Where you want to plant take a narrow rod and stick down into the ground to locate the line. Usually 3/4-1 inch PVC. These lines are not buried that deep. Usually less then a foot. Plant accordingly. Give the sprinkler heads some distance and avoid them washing down the tree/trunk when in operation.

The roots of the pines will NOT hurt the PVC sprinkler lines. As ken pointed out, a shovel is likely to do more damage, but usually that doesn't happen unless you're using powered equipment to dig the holes.

It's a bummer when the sprinkler lines dictate where the trees will be planted, or any plants, for that matter.

In doing yard makeovers I have taken out sprinkler heads and replaced with soaker hoses or drip systems, leaving some heads where appropriate. It's a much more efficient water delivery system. It also allows more freedom in plant placement for a better design.

Mike

my one inch supply lines are NOT pvc ... black poly vinyl or some such ...

if you have 5 mins to waste.. my supply line is like this stuff

https://www.youtube.com/watch?v=zPzUoAma7Yc

if you dont know whats down there.. time to dig a hole and find out ... any chance you can find out who the installer was .. and interview them???

ken

The link doesn't work for me but it sounds like the one inch black polyvinyl pipe that is generally used for the incoming water line to the house. I use it also as my main supply line to my timer controlled sprinkler valves. From there I used 3/4 inch PVC. If not many heads on a zone I used 1/2 inch PVC.

I always tried to install the lawn sprinklers in a bed rather than out in a lawn. Less broken heads and trimming that way.

Mike