Low-voltage garden lighting

Often heralded as a new development is low-voltage (l-v) light-ing. It’s really not new -for decades it has been used for automobiles – but in a garden it is a relatively new concept and, with today’s equipment, it can bring exciting advantages.

One of the most important advantages is safety. If a child removes the bulb from any 12-volt garden light fixture and pokes his fingers inside, he won’t receive a dangerous electrical shock. Another important advantage is the ease of installation. For L-V lighting you need a transformer to reduce 120-volt household current to the 12-volt current required. Most modern garden-light transformers simply plug into any outlet. From the transformer on, the 12-volt wiring is buried a few inches in the ground, strung along fences or run up tree trunks -without the need of conduit or protected cable, as would be necessary with 120-volt wiring.


Low voltage garden lighting also allows you to have what is called low-key lighting. Low-key lighting is not only ample for illumination but is extremely flattering to a garden patio or entryway in its visual effects. It lets you create soft shadows and silhouettes with plants and accent architectural features-quite the opposite from what is achieved with floodlights. With such floodlighting an entry or garden is strongly illuminated for a short distance away but the light is flat and monotonous.

Creating low-key effects is a matter of experimenting with liaht in different places and different ways in your garden. With L-V equipment, you can simply string the wiring on top of the ground, and leave it there for weeks, if necessary, until you decide exactly where each fixture should be placed.


Each garden is different, but here are some factors that lighting experts keep in mind on almost all L-V installations:

1. Try to use six or more small lights throughout your garden, rather than two or three more powerful lights.

2. Place lights out bevond your patio. There, they create depth in the garden, and they draw insects away from the patio.

3. Install separate switches for bright ‘activity’ lights, such as near a barbecue or table tennis area, so they can be turned off when not needed.

4. Consider using a few small lights on a fence or hedge, if needed, as a curtain between your garden and a neighbor’s.

5. Light the hazards (softly) as well as the attractive features. You know where a garden step is, but guests may not.

6. Use submersible fixtures in wet areas and garden pools, or else waterproof the connections thoroughly with a rubber seam compound. You can place any L-V fixture in water, but exposed connections will corrode and fail in time.


Installation of L-V wiring is done in two steps. First, you connect a 12-volt garden transformer to a 120-volt outlet. Second, you run the low-voltage wiring out from the transformer to low-voltage light fixtures you have bought or made.

It’s best to choose a transformer of about 100-watt capacity for your garden and patio -so you can run several lights (depending on size) from it. If you have a large lot, you may want to have a second garden transformer on the front side of the house, perhaps smaller for two or three lights. Avoid using doorbell transformers; most of them are unsafe for this use.

Try to install each transformer at some central location, so two or more short cords can run from it to your lights, rather than one lengthy cord (there is more line-loss of current at 12 volts than at 120 volts). With the two-wire No. 12 cord generally used on low-voltage garden lighting, a run should not exceed 100 feet. If it needs to be longer, use heavier cord.

Installing the transformer. This can be done in several ways. The simplest is to obtain a transformer with a weatherproof case and plug-in cord, and just plug to an outlet on the patio, house exterior, or in the garage -as if it were a lamp.

If the outlet you choose is not controlled by a switch inside the house, you can use a transformer with a built-in switch. But this means that you will have to step outdoors to turn the lights on and off at the transformer, so it is usually better to rewire that outlet for a switch indoors. If you are not familiar with house wiring, have an electrician do this job.

Still another approach is to use automatic switching. You can buy L-V garden-light transformers today with built-in timers that automatically turn the garden lights on and off at any desired hours each evening. Or you can include a photo-electric switch at the outlet that will turn the lights on at sundown and off at dawn. With either, the efficient L-V lights use so little current that the expense of their being on for some extra hours is negligible.

Installing the wiring. The 12-volt cables running from the trans-former to your garden lights are usually a ‘zipcord’ type, similar in appearance to the cord for an electric toaster, only slightly heavier (two No. 12 wires) and with more weatherproof insulation.

You can bury these cords in the ground (in fact, it’s best, as they then are protected from the sun). Place them 6 inches deep where possible, and try to run them alongside walks, fences, planter-bed edgings, and water lines, so you will not dig them up when cultivating.

Where a cord needs to cross a lawn, cut a slit-type trench, wedging it open with your shovel. Push the wire down into it and then tamp the turf back in place.

You can connect your garden lights along the main cords (some fixtures simply snap on), or you can run stub lines to different fixtures. The latter is preferable when you wish to install a fixture upon a fence or above an entryway, because you do not need to run the stub line farther to other lights, and it can be a small cord, even the No. 18 zipcord used on table lamps. You can hide this cord quite easily along wood and masonry joints, and along moldings.

For a fixture in a tree, just staple a cord up the back side of the trunk. Attach it loosely to allow for the tree’s growth.

You can connect a stub line to a main cord with soldered joints, or screw-on or crimp-on connectors. With the latter two, coat the finished connections with any rubber seam compound – not for shock protection, but to prevent fertilizers and the like from corroding the connections.

When you stake a light fixture in the ground (rather than at-taching it to a wall or other structure), bury at least a foot of slack cord alongside it to provide for future adjustments of the fixture as the plantings around it grow.

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