I was meeting with a client this weekend and I asked if they had plans to add landscape lighting to the backyard. She replied “oh yes, and we already had the wire installed.”
People, don’t do this.
Pre-wiring makes a lot of sense inside the home to prevent the alarm installer or cable guy from having to knock holes in the drywall. The thing is, those wires are pretty safe once they’re installed behind the drywall. That little strand of direct burial cable 6-12″ down in your beds? It’s not safe at all. If your beds are “prewired”, I’m going to look at that and wonder how many times that line has been severed and spliced when your beds were edged. I’ll ponder how many times a trowel or shovel nicked the insulation on that wire, setting you up for a shirt circuit. Besides, is the wire sized appropriately for voltage drop? Is it going where we need it?
In short, prewiring for landscape lighting doesn’t help. Most installers aren’t going to be interested in using it, because if they’re standing behind their system they’ll want control over all the components. Instead, save your money and buy yourself a garden gnome. I highly recommend one decked out in Red Sox gear.