Note: The original draft of this post was written on December 8, 2018.
Edges define and create spaces, and these spaces can become important design elements, in a landscape, along a roadway, or in the home garden.
In his book Introduction to Landscape Design, John L. Motloch describes the concept of spatial edge, noting that “the spatial edge near eye level is crucial in visual perception.” Expanding upon this idea, Motloch continues:
“Successful spaces usually have edges that screen external elements that would otherwise destroy desired sense of place and that enframe views to promote this sense. Unsuccessful spaces tend to have poorly defined or improperly formed spatial edge. Spatial edge is important in helping people discover space in an appropriate manner.”1

On a recent drive along the Blue Ridge Parkway, the value of spatial edges was easy to appreciate. Sloping, winding, neatly maintained buffers of grass separate the pavement from the trees, a visual framing that creates a foreground and makes it easier to appreciate the woods of the Parkway and the mounds of mountains in the distance. The grassy shoulders are designed to flow naturally, following the curve of the Parkway and the rise and fall of the land, and the movement is mesmerizing.

Without the shoulders the drive would be a lovely meander through the woods, and that’s what we found along other roads in the area, particularly when crossing the Pisgah National Forest, and when hiking certain trails in the southeastern quadrant of nearby Great Smoky Mountains National Park. The trees are close, filling one’s entire line of sight. The road or trail provides a narrow slice of perspective, with trunks and branches and leaves within reach, and the result is beautiful and serene. But the feeling is not the same as when viewing a scene with a well-crafted spatial edge.
Brookside Gardens in Montgomery County, Maryland presents another example of this principle. Look across the lawn sloping down to the woods of tulip trees and oak and hickory. A pond and Japanese tea house and rock garden with conifers rest in the middle view of this extensive buffer. Here you’re able to see what cannot be seen when on a trail in the woods of the same park – the edge, which exposes the full length of the trees’ trunks, the density with which they’ve grown to create the woodland, and the cloud-like movement of their crowns. The setting sun creates shadows along the ridges of the bark and reflects off the turning leaves. It’s a composed scene that creates a kind of living painting, a completely different sense from being in the midst of the woods.

What appears to be a simple design practice – creating a buffer for viewing – transforms these landscapes. Remove the space created by the edge and the response to the scene would be completely different.
It’s a useful exercise to keep in mind when walking around a public park or your own garden. Imagine the scene with and without a defined edge or buffer – the stretch of lawn, the mulched bed, the fence or wall – and consider the impact on the viewer. It’s remarkable how even the most ordinary of views and basic combination of plants can improve when controlled through the use of a thoughtful edge.
Notes
1. Motloch, John L. Introduction to Landscape Design. Second Edition. John Wiley & Sons, 2001. p. 190.
If you’d like to read more…
“Brookside Gardens.” Montgomery Parks. Montgomery County Department of Parks. Accessed December 9, 2018. https://www.montgomeryparks.org/parks-and-trails/brookside-gardens/
“Designing the Blue Ridge Parkway.” Blue Ridge Parkway. National Park Service, U.S. Department of the Interior. May 31, 2016. Accessed December 9, 2018.
https://www.nps.gov/blri/learn/historyculture/designing-the-blue-ridge-parkway.htm
Ford, Mike and Liz Sargent. “The Blue Ridge Parkway: Exemplifying the Evolution of the NPS Planning and Design.” National Center for Preservation Technology and Training. National Park Service, U.S. Department of the Interior. This presentation was part of A Century of Design in the Parks: Preserving the Built Environment in National and State Parks, June 21-23, 2016, Santa Fe, New Mexico. Accessed December 9, 2018. https://www.ncptt.nps.gov/blog/the-blue-ridge-parkway/
Photo Attributions
All photos were downloaded from Pixabay and are free for commercial use with no attribution through a Creative Commons CC0 (Public Domain Dedication).