Landscape Lighting in Phoenix: What an Electrician Wants You to Know

Landscape lighting in Phoenix has a tougher job than it does almost anywhere else. Fixtures sit in rock and gravel that bakes all summer, wires run past irrigation lines, monsoon storms push water and dust into every opening, and the sun breaks down plastic in a few seasons. The good news: most of the problems we see come from a few planning mistakes that are easy to avoid if you know about them before the first trench is dug.

Low-voltage vs. line-voltage landscape lighting

Most residential landscape lighting in Phoenix is low voltage. A transformer steps 120-volt house power down to roughly 12 volts, and a direct-burial cable runs out to the path lights, uplights and well lights. Low voltage is safer to have in the yard, easier to adjust, and with LED fixtures it uses very little power. It's the right choice for lighting trees, cactus, walls and walkways.

Line-voltage (120V) lighting is the same power as the outlets in your house. It's what feeds wall sconces by the patio, motion floods over the garage, ramada fans and lights, and post lights at the end of a long driveway. Because it's full household voltage, it has to be run in approved conduit or cable, buried at proper depth, protected where required, and in most cases permitted and inspected. This is work for a licensed electrician, not a weekend project.

Many good designs use both: low-voltage for the landscape and line-voltage for the house and patio structure. Plan them together so you're not trenching the same yard twice.

The outdoor outlet and transformer: where most problems start

A low-voltage system is only as good as the outlet it plugs into. We regularly find transformers plugged into an old outdoor outlet with a cracked cover, a non-GFCI receptacle, or an extension cord running from the garage. Outdoor receptacles need GFCI protection and a weatherproof cover that stays closed while something is plugged in, often called an in-use or bubble cover. If you don't have one where the transformer needs to go, adding a new outdoor circuit or outlet is usually a small job.

If the transformer keeps shutting off, or the GFCI trips every time it rains or the sprinklers run, water is getting in somewhere. That's a symptom to chase down, not reset forever. Why a GFCI keeps tripping and what it's telling you →

• Size the transformer with headroom. Add up the wattage of every fixture and leave room for a few more. A transformer running at its limit in a hot side yard won't last.
• Mount it in the shade if you can. North- or east-facing walls are better than a west wall that bakes all afternoon.
• Watch voltage drop. Long, thin wire runs leave the last lights dim. Shorter home runs or heavier wire keep the far end of the yard as bright as the near end.

What the Phoenix climate does to outdoor lighting

Heat, sun and monsoon storms are the three things that kill outdoor lighting here. LED drivers don't like heat, so fixtures rated for outdoor and wet locations and built from metal last much longer than bargain kits. Sun fades and cracks plastic lenses, housings and wire jackets that are left exposed. Monsoon rain and blown dust find any splice that wasn't sealed with proper waterproof connectors, and corroded splices are behind most "half the lights went out" calls.

Desert yards add their own hazards. Rodents and pack rats chew exposed wire, decorative rock shifts and cuts into cable over time, and drip irrigation keeps some fixtures wet every day. Burying cable properly, keeping splices in accessible spots, and keeping fixtures out of the spray pattern of emitters prevents most of it.

When you shop for fixtures, look for ones listed for wet locations. The ENERGY STAR light fixtures page is a useful neutral reference for efficient fixtures and what the label means.

Landscape lighting in Glendale and the West Valley

In Glendale, Peoria and the rest of the West Valley we see two kinds of homes. Newer neighborhoods like Arrowhead Ranch often have an HOA with guidelines on exterior lighting, so check them before buying fixtures, especially bright floods aimed toward a neighbor's yard. Older homes near downtown Glendale may have just one outdoor outlet, sometimes without GFCI protection, which is the first thing to fix before adding a transformer.

Wherever you are in the Valley, aim light down and at what you want to see. Uplighting a palo verde or mesquite, grazing a stucco wall and marking a path looks better than one bright flood, and it keeps the glare out of your neighbor's bedroom window and out of the night sky.

Design tips that look good and stay safe

• Light the path edges, steps and grade changes first. That's the safety lighting.
• Then pick two or three features to highlight, such as a tree, a saguaro or a boulder group.
• Use warm color temperatures (around 2700K to 3000K) so stucco and plants look natural.
• Light the front door and house numbers so guests and emergency crews can find you.
• Put patio and ramada lights on their own switch, and the landscape on a timer or photocell.
• Plan an extra outdoor outlet for the patio while the trench is open, for holiday lights or a mister. Can your outlets handle holiday lights? →

DIY or hire an electrician?

Plugging a pre-built low-voltage kit into an existing GFCI outdoor outlet is a reasonable DIY job. Anything that involves new 120V wiring, such as a new outdoor outlet, wall or post lights, a ramada circuit or a hard-wired transformer, should be done by a licensed contractor. You can confirm any contractor's license on the Arizona ROC contractor search.

Planning outdoor lighting this fall?

Send us a few photos of the yard, where your outdoor outlets are, and what you'd like to light. We'll tell you what the existing wiring can handle, what needs to be added, and give you a free written estimate. B and D Electric LLC is licensed and bonded, Arizona ROC 361086, and our two owners have more than 40 years of combined experience. See our lighting installation and residential electrical services. Call or text (480) 828-1181, or request an estimate.