Outdoor Landscape Lighting
Thoughtful landscape lighting extends our living space outdoors and can give us an entirely new view to enjoy at night, whether we are inside looking out, or outside enjoying our private gardens and public parks. Landscape lighting expert Janet Moyer shares her insights on how to use lighting to connect us with the land around us.
Q. What considerations should be taken into account when lighting a residential landscape?
A. Landscape lighting is not easy. It creates a night environment to enjoy while outside on your patio, for guests to enjoy as they arrive, for dinners sitting by a pond or a stream—whatever your landscape offers—but also to enjoy as an artistic view looking out from the windows while you are indoors at night. You want to think about what you can see out your windows and what you would like to see from your family room window at night. It may be simply one tree, or one sculpture, or a “scene” composed of a tree, the planting under the tree, and a hedge at the edge of the property. These are some of the aesthetic issues to consider when letting light provide you with connection to your landscape at night. There are other considerations as well. For example, are there any obstacles in your landscape that need to be clear to you and your guests when you are outside at night (stairs, for example, or a change in grade on the property)? You’ll want to consider anything that helps make your space feel safe and provides you with a sense of security.
Q. Where is a good place for homeowners to start?
A. First you need to consider budget. Landscape lighting is not inexpensive—especially now that lighting is changing to electronic light sources like LEDs. So, you need to prioritize your needs and desires. This allows you to start with the most important and build on your landscape lighting over the years as you can afford it. The first thing to spend any money on is power distribution. After that’s provided throughout your landscape, any place you may want landscape lighting over time, then you can start locating and installing lighting fixtures. This may be all you do the first year, especially when building a new home or renovating a garden.
Costs vary widely with landscape lighting fixtures and associated equipment such as low-voltage transformers. You need to be very careful in selecting equipment because the outdoor environment is very destructive—for example, there are eight kinds of corrosion we need to try and prevent in the design and construction of light fixtures.
Q. What are the main types of landscape lighting and the advantages of each?
A. While there are many approaches to landscape lighting, the main approach, even today with LED, is using low voltage. This is partially a power distribution issue—low-voltage, typically 12 volts, provides more flexibility in power distribution and fixture location, as conduit is not required and the burial depths are shallower than 120-volt and less dangerous. We are all considering green issues today, and being off the grid is very enticing. In landscape lighting we are getting closer to that being a reality with the significantly reduced power consumption that LED sources offer, but storing power for landscape lighting fixtures with well-shielded sources, good construction, and the functionality to last for years is still not there yet.
Q. What are some common landscape fixtures? What about sources? What should consumers look for in terms of color and wattage?
A. Landscape lighting fixtures can be stake-mounted, below-grade, tree-mounted, building-mounted, a hanging fixture—there are many types of fixtures. And, again, they vary widely in cost, construction, and functionality. The biggest issue for someone not familiar with lighting is knowing enough to be able to select a fixture that will suit your needs.
Today, landscape lighting has substantially transitioned from traditional light sources of halogen/incandescent or HID to the newer electronic LED sources. We have both LED MR16 (and other types) replacement lamps, which replace old technology or existing lamps in gardens with landscape lighting and LED integral module sources. Integral module LED sources are being designed in conjunction with both existing shaped fixtures and brand new fixtures. Many fixtures with integral module LED offer individual fixture output dimming, allowing the fixture to provide exactly the right amount of light for a specific location, and some are starting to have optics that can vary.
Having individual fixture light output variation is a benefit that we have never had in landscape lighting. This does not mean that a fixture cannot then be dimmed with/through an overall project control system—most can, but not all. With integral module LED, most fixtures today have interchangeable optics from 10° or 15° beam spread, considered a spot to a narrow flood in the range of 20-25°, then a flood from 30-40°, and a wide flood from 60-100°. In landscape lighting we need variable beam spread and light output.
In our change from traditional sources to LED we have lowered the wattage we need dramatically. While previously we would have used a very high-wattage 37-watt halogen lamp, now we would use between 8-12 watts. We don’t need much light once our eyes have adapted, and so the typical wattages we use for most of the elements in landscape lighting varies from 5 or 6 watts down to less than 1 watt. Our energy consumption has dropped by 70-80% from halogen projects. And those existing halogen projects can be retrofitted to LED and drop the total wattage, again by as much as 70-80%. This is significant and worth considering. We have come that far with the development of LED. However, not all sources that we have in our landscapes can be replaced today. The MR16 can be easily, but more unusual lamps haven’t been developed enough or at all yet.
With most residential projects, what I am recommending to my clients today in color temperature is 3000° Kelvin. It is a little bit “colder” than our halogen lamps, but with more blue and green, and it looks great on plant materials and is better at color rendering than the lower temperature of halogen, typically in the range of 2700°K to 2900°K. In interior residential spaces, you really have to look at it and visually understand how the light source affects your environment. Because we like to dim interior lighting, we have become very comfortable with a more “yellow” light appearance, and 2700°K is a good starting point for many interior residential spaces.
Q. What do you think is the biggest challenge in creating a successful lighting design for a residential landscape?
A. The biggest challenge in landscape lighting is understanding that it is complicated, not inexpensive, and requires maintenance. If you want landscape lighting, you need to understand how to do it right—plan for the cost and commit to maintaining it. Normal maintenance does not require a lot of work (keep the aiming doing what it is intended to do; remove debris from covering the fixtures’ lens), but there are long-term issues that have to be considered from the beginning. For example, this year we’ve had a difficult winter on the East Coast. We have had substantial heaving of our ground that has physically moved landscape lighting fixtures and changed the aiming. This means that in the Spring, we have to review the entire system to make sure it is working as originally planned.
In addition, plant material changes over the seasons—new flowers and leaves in the Spring, Fall color, plants growing, plants dying. People make changes in their gardens. So, from the beginning, the power infrastructure needs to be planned to respond to all kinds of changes, as do the fixtures, which is one reason why low voltage is prefer to 120-volt or “standard” voltage. Using a stake-mounted fixture allows you to literally pick a fixture up and move it as the plant it is lighting grows and changes size and form.
Landscape lighting requires thoughtful planning, including controlling light from leaving our property and going into our neighbor’s or overwhelming the night sky. These things don’t happen with good landscape lighting because we use so little light and aim it onto surfaces, not into the sky. Most importantly we shield the light source inside a fixture so that we are not overwhelmed with too much light or glare from the fixtures in our yards.
Q. How do you strike a balance between aesthetically pleasing landscape lighting and lighting that maximizes safety?
A. We are starting in a dark environment with no ceiling, but instead a dark sky and no walls, so our eyes adapt to a much lower light level than we have inside our homes. Our eyes shift their visual response from what is called “photopic,” or high light levels, to much lower light levels in the range called “mesopic,” and sometimes as low as “scotopic.” The cones in our eyes are receptors in night light levels that see color, shape, etc., and in low light levels, our rods see movement and variation in light level—what we need in a dark, scary space to avoid anything that could attack us. So, landscape lighting has to be set up to help us see and feel safe in low light levels. We need to see the environment and its boundaries, including vertical elements of the space such as shrubs, sculptures, and walls because humans see vertical surfaces before horizontal surfaces—such as the ground, a pathway, our lawns. We need to see any obstacles or grade changes. When landscape lighting addresses these issues aesthetically, you can have both safety and beauty in the same lighting design. That is what I think we should all be striving for in planning our landscape lighting. We have to opportunity to stay connected to our garden spaces, in the country and the city, and we should take advantage of that opportunity.
Janet Lennox Moyer, IALD, is an internationally known lighting designer and recipient of many design awards. She has judged lighting competitions and been published extensively in magazines, newspapers, and books. She has taught all over the world since serving as teaching assistant for her undergraduate lighting course at Michigan State University.
Moyer’s practice has included interior, commercial, and residential lighting, but her emphasis shifted to landscape lighting in 1983. Moyer taught landscape lighting at UC Berkeley and Rutgers University in the Landscape Continuing Education departments during the 1980s and the 1990s. She studied plant identification, plant propagation and pathology, garden design, and layout at UC Berkeley, Merritt College. At her current 5-acre property in upstate New York called Saluki Park, she continues the work of the original property horticulturalist plants-woman, Helen Frane, who provided the garden bones in the 1920s.
Her projects include landscape lighting of Levi Plaza (San Francisco); the Detroit Civic Center; several city blocks in downtown Tacoma, Washington for Pierce Transit incorporating a 200-foot-long “Waterwall”; interior lighting at the Skywalker Ranch (Nicasio, CA); and for a palace in Abu Dhabi; both interior and landscape lighting at the Far Niente Winery (Oakville, CA); a resort in Safaga, Egypt; and many special residential properties across the nation. Recently completed projects include several areas of both the Chicago Botanic Gardens and the Olbrich Botanical Gardens, in Madison, Wisconsin; a Palm Aboretum and Conservatory in Northern California; private homes and gardens from the Hollywood Hills to Maine, from Montana to Bermuda; several estates in New York; and an abandoned marble quarry in Vermont. Moyer is the author of the internationally acclaimed professional book titled The Landscape Lighting Book.
In 2010 she began work to create a non-profit public charity to preserve and disseminate information about landscape lighting. The International Landscape Lighting Institute (illi) has designed and built a permanent Landscape Lighting Exhibition, which opens to the public this year.