Southwire 18/7 — Multi-Conductor Sprinkler Wire (100 ft, Direct Burial Rated)

What is it and what's it for?

Think of it like an old multi-pair telephone cable, but for irrigation: inside a single jacket there are 7 individual wires, each a different color, plus one common return wire — so one buried cable carries the controller's 24V AC signal to up to 6 or 7 separate solenoid valves, each wired to its own conductor, without burying a separate cable for every valve.

Real-world use cases

• At home: You're adding a new drip zone at the back of the yard and the cable the original installer left only had 4 wires, all already used by existing zones — instead of digging a brand-new trench end to end, you cut the length of this cable you need and add the new valve to a spare wire, without touching the wiring for the zones that already work.
• In a business or workshop: An irrigation installer setting up a new 6-zone system at a house uses a single roll of this cable to connect all 6 valves from the valve box back to the garage controller in one pass, instead of buying and running 6 separate cables — saving hours of trenching and labor on every install.

How to avoid buying the wrong one

• Count how many valves you need to control and pick the wire count accordingly (or one more, for future zones) — this one has 7 conductors, enough for up to 6 valves plus common; for bigger systems, 8- and 10-conductor versions exist.
• Measure the real distance between the controller and the farthest valve before buying by length: at 18 AWG, runs well past 150 feet can lose voltage along the way and make that valve open weakly or not at all — that calls for a thicker gauge (14 or 16 AWG), not this one.
• Confirm it's specifically rated "direct burial" like this one — ordinary hardware-store electrical cable meant for indoor use degrades quickly underground with moisture, even if it looks just as thick at a glance.