Summary: The terms “fill light” and “spill light” is lighting supplied from other lighting placed in the garden or in a patio area. It can be landscape lighting or other reflected light.
Question: Recently I heard the term “fill light” and “spill lighting” used for patio landscape lighting, what exactly is it? I have heard of solar lighting but not “fill lighting.” Monica, San Diego, California
Answer: Monica, “fill light” or “spill light” is best described as pleasantly supplied lighting which “spills” light from near-by garden lighting.
For example, a terrace or patio surrounded by a planting of low-growing evergreens where the lighting of these is from low voltage outdoor lights to set off the perimeter of the patio/terrace, at the same time spilling enough light onto the terrace floor to provide a pleasant glow of light easy on the eyes, yet bright enough for pleasant conversation or relaxation.
In the same way, potted plants or shrubs often can be lighted with a small top-shielded bulb to provide a lively accent, at the same time spilling additional light onto the covered terrace.
And don’t forget the light available from adjoining windows that open onto well-lighted interior porches or other rooms. If shades or sheers are used on these windows, use a type that will allow light to filter through even when drawn for privacy.
Make full use of light-colored house walls, fences, or other reflective surfaces adjoining your terrace or patio. By proper light placement, these surfaces often reflect a pleasant glow of indirect light eliminating the need for one or more additional floodlights.