I just completed a large residential landscape project and I find that quazite boxes [fiber concrete w/ open bottoms] work the best, just make sure they are installed with drainage gravel underneath.
I pipe the trunk runs from end to end in pipe, type dictated by depth able to dig and AHJ.
I pipe from these boxes to a local point in garden beds or yard space then branch out in UF to each individual light. Rocket posts work the best, and with UF, relocating is easy. In a few spots on this job, I had to set the rokets in concrete due to depth issues. I just sleve the UF thru some pipe/flex and all is good.
For splicing, Ideal makes weatherproof wire nuts, 2 to a blister pack. Saves MANY headaches.
In tree lighting aplications, I use flex to a FS box, then flex to the required 8' above grade to a box or change over for cord.
oh yeah, as always I get the customers sprinkler contractor to do the digging, and if they don't have one I reccomend a couple of names to them.
