SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

I'm not understanding your logic. By that, I mean exactly what sort of a product are you looking for. The reason I say that is on the surface of it, if you are going to add zones to your existing one-zone system, you will have to either run more pipe from the hose bibb to the 2nd zone, or you are going to need to install multiple valves down the existing water line where you want to split off additional zones. Installing multiple valves down the line is going to either require that you run some burried wire out to the valves (cheap) or have some sort of battery powered valves or remote control (wireless) valves. While such things do exist, unless you are talking about miles of wire, running some burried wire seems cheaper.

My personal suggestion would be to ditch the black pipe (if this is something simply laying on the ground) and install some true burried irrigation pipe (like white PVC pipe) from the house to the garden, and install a burried manifold out by the 1st garden where you want to start splitting the water to the various zones. While you have a trench open from the house to the 1st garden, you can install the wiring needed for the manifold out in the garden. It so far sounds like a very much DIY sort of project, and can possibly be done for about $200 (depending upon what you have to do for the trench). Obviously the trench can be hand dug for the cost of a shovel and asprine for you back. If the ground isn't too hard, places like Home Depot have some simple trench diggers that rent for $50 or less (it works sort of like a saw blade, cutting into the soil, but you have to provide the muscle to push it forward). If you have some really hard soil, then you'll want to spend the $125-150 to rent a full blown trencher for the weekend. They have blades that can cut 24" deep (twice as deep as you would need to consider) and move forward (actual backward) under their own power. They can initially look intimidating to operate, but if you only need to dig a strait trench they are not very difficult.