Installing outdoor lighting can be simple

By G. Owen Yost

If you spend a chunk of money on new trees, shrubs and flowers, you probably want to enjoy them at night too. Putting in outdoor lighting, however, might be a scary experience. But not if you use simple, low-voltage lighting.

Complete low-voltage lighting kits are available at home supply stores, or you can buy the items separately (fixtures, cables etc.) if you want to customize your yard’s appearance. The most critical item is a step-down transformer, which changes your home’s 120-volt alternating current (AC) into 12-volt direct current (DC). At this voltage, the direct current electricity is too weak to seriously hurt you, but still strong enough to perform a small task, such as lighting your yard. Just make sure you pay attention to the bulbs you use, and the length and size of the connecting cable.

HINT: The wattage of your transformer should be about 20 percent higher than the total wattage of all the bulbs.

The cable, which looks like a super-sized electrical cord, is measured by gauge: 10, 12, 14, 16 or 18. The lower the number the thicker the cable, and the more electricity it can carry. Typically, landscape lighting cable is "direct burial", meaning it can be buried right in the soil, and doesn’t need to be enclosed in any sort of conduit. Nor is it affected a great deal by sunlight, which makes regular cable brittle.

Fixtures are available in all sorts of styles and sizes: spotlights, subtle pathway lights, stairway lights, you name it. They should be made of sturdy, rust-resistant material such as thermoplastic, cast aluminum, ceramic or copper. These can survive the weather, as well as errant swipes from garden tools. Fixtures simply clamp into the cable, wherever you want them, by means of tiny "pins" that pierce the cable’s self-healing covering, connecting with the current.

The bulbs that go in the light fixtures normally range from 5 watts to 75 watts. They’re smaller and last longer than ordinary household light bulbs. Using the lower-rated bulbs lets you have more bulbs, while avoiding the "penal colony" look that’s so common with overlit yards.

HINT: Avoid bathing everything in light. Whatever you leave in the shadows is just as important as what’s lit up.

The entire lighting system connects to a weatherproofed outlet, with a ground-fault circuit interrupter (GFCI). Often the GFCI is built into the transformer. Many transformers even have timers to let you control when the lights go on and off. The transformer should be mounted in a protected spot, off the ground, near the outlet. (Never use extension cords).

Before you install a thing, design a lighting plan on paper by making an accurate drawing of your property and deciding where the lights will be. Then measure the distance from the transformer to every proposed light fixture, using straight lines whenever possible. Simply measuring the plan tells you how much cable you’ll need (Buying some extra is a wise idea.)

HINT: Don’t feel that you have to turn night into day.

When the plan is ready, and you have all the pieces, run the cable (on top of the ground for now) where it needs to go. With the transformer still unplugged, attach bulbs to the light fixtures, and attach the fixtures to the cable. Wait until evening to plug in the transformer. Adjust until the results are satisfactory.

Bury the cable using a straight-bladed spade by slicing a trench about 4 to 6 inches deep, at about a 45-degree angle, then pushing the cable into it by hand.

HINT: Also bury pieces of brightly colored caution tape to alert adventurous or forgetful shovelers in the future.

While it’s easy to install, it’s also easy to do wrong. So I urge you to make any changes and mistakes on paper (via the lighting plan) when all you need to correct them is a few strokes with an eraser.

Owen Yost is an area landscape architect specializing in designing low-maintenance landscapes while incorporating native plants with hardscape. He is a member of the American Society of Landscape Architects, Keep Denton Beautiful and the Native Plant Society of Texas. His Denton office is at 4516 Coyote Point; call 940-382-2099 or 940-383-9655 or e-mail him at Yost87@charter.net