Little used in the Pacific Northwest except for highway projects, a terrific landscape construction device called a gabion wall is used to great effect in gardens and parks in Europe. Gabion walls can either be free-standing space dividers or they can retain steep slopes. The concept is simple: rather than using heavy, giant boulders to retain soil, you make a metal wire cage and fill it with much smaller rocks. The inert mass of the caged rocks holds the slopes in place.
For an enterprising client in Bellingham, Washington who had admired gabion walls when she lived for several years in Germany, Seattle landscape architect Brooks Kolb designed the three-tiered wall system pictured below at the client’s cottage overlooking Bellingham Bay.
Although gabions are usually filled with any commonly available rock, Ocean Pearl stone from Marenakos Rock Center was selected to line the top and front of the cages, while basalt rock filled the invisible backs. The blue-gray color of the Ocean Pearl stone harmonizes with a similar retaining wall in the back garden. The planting terraces behind the gabions were backfilled with drain rock and a top layer of organic soil to provide an extensive rooting zone for a diversity of shrubs and ground covers. When finished, the end result will be an elegant terraced slope unlike any landscape in the neighborhood. Rock construction was by Russ Beardsley (see related blog article), and the custom fence was built by Tony Keslau to a design by Brooks Kolb.
Gabion Walls in Progress, March, 2013
Planting Nearly Finished, September, 2013