There are real advantages to using quality outdoor landscape lighting wire. Quality wire will save you both money and time. But how can you tell the good stuff from the bad? Here are 5 easy tips for selecting high quality wire for outdoor lights.

Technically, any 2-strand wire (even speaker cables!) could be used for outdoor lighting. But you wouldn’t want to use just anything, because you’ll end up with problems such as uneven lighting due to voltage drops, and electrical shorts which can be a real pain to track down and fix.

As a rule of thumb, for landscape lighting projects you’ll want to use UL-listed “12/2 wire” (in other words: 12 gauge wire, with 2 strands). But the aisles are full of wire all claiming to be great for outdoor lighting. How can you spot the good stuff?

Here are 5 things to look for when selecting your outdoor landscape lighting wire:

Spools of wire for outdoor landscape lighting
Spools of outdoor wire
(Click to view full size)

1. DIRECT BURIAL

Wire labeled as “direct burial” or “underground” is specifically designed for installing underground where it will be exposed to the elements. The water and chemicals in soil will eat away at the insulation sheath, and direct burial wire better withstands this year round attack. Specifically important here in Canada, direct burial wire will much better resist stiffening and cracking due to cold. Look for the words “direct bury” or “underground” printed right on the wire.

2. SUNLIGHT RESISTANT

You might wonder why you need your wire to resist UV rays when it’ll be underground? Because it’s easy for you or your gardener to expose a small length of wire when turning your soil. Often this goes unnoticed since it’s black wire against dark soil or mulch. The sun will attack that exposed length of wire, which causes polymerization. In layman’s terms, it’ll turn the insulation sheath into goo. That can lead to corrosion and short circuits which are maddeningly hard to track down. Look for the words “sunlight resistant” or “UV resistant” printed on the wire.

3. HIGHER VOLTAGE CAPACITY

A quality wire should be rated for a much higher voltage than you will ever expect it to handle. Higher voltage ratings are not just good safety, they’re a handy rule of thumb to separate the quality landscape wire from the low grade stuff. Look for wire that says it’s rated to handle 150V, and as with all these tips only trust the words printed directly on the wire itself not just the claims of salespeople and web site. Look for a higher voltage rating such as “150V” printed on the wire.

4. FLEXIBILITY

Some wire is far more flexible than others, and often a good strong UV-resistant sheath makes a wire hard to bend. This makes snaking the wire around your garden much more difficult. Look for a highly flexible wire with a PVC sheath that’s very pliable. Unfortunately, if you’re buying from a big box store you often have to choose between quality and flexibility. A professional outdoor lighting provider can supply you with wire that is both strongly UV-resistant and highly pliable. Flexing the wire by hand is the only way to test this for yourself, which makes buying wire over the internet more difficult.

5. DISTANCE MARKERS

Part of a successful outdoor light design is taking into account zones of fixtures, so you can evenly distribute voltage. This is true for both LED and halogen, although halogen bulb are more dramatically affected by “voltage drop”. Any quality wire will have distance numbers printed every foot so you can keep track of wire lengths when you are load-balancing your system back at the transformer. Look for distances printed every foot along the wire.

High quality outdoor light wire
High quality outdoor light wire
(Click to view full size)

Pictured to the right is an example of a high quality landscape lighting wire that meets all 5 of the above criteria. Click the photo to see how the details are printed right on the wire itself.

It’s relatively easy to replace an outdoor light fixture if it gets damaged, but when the problem is a tiny crack in a wire “somewhere” on your property, it can take hours of frustrating digging to hunt down the problem.

You’ll save a lot of time in the long run if you use quality wire for your outdoor lighting.

Outdoor landscape lighting wire is available from many places, including big box stores, electrical supply shops, some landscapers and sprinkler companies, and of course from professional outdoor lighting installers such as Outdoor Lighting Perspectives in Toronto.