Adventures in landscape design
Fact 1. Here in the Pacific Northwest, it rains.
There’s a good chance, that despite the record 80 mostly dry days we had this summer, it’s raining while you are reading this column.
Fact 2. Any wood product, pressure treated or not, will eventually start to rot in our climate.
That was the challenge faced on a recent landscape design project in a Mukilteo yard.
The entire west side of the yard consisted of multiple levels of terraced planting beds, supported by decomposing railroad ties.
A drive through the neighborhood revealed several old railroad tie walls in similar states, so perhaps there are some readers out there who may be interested in some of the options that were considered for replacing the old walls.
My client was interested in something with an urban loft type of look and had used some elements of steel in part of the interior and was intrigued with the idea of repeating this in the landscape.
One of the first materials that came to mind was Corten steel. This material comes as steel panels or prefab planters. Corten steel has a warm, weathered look.
It is a recycled steel product that oxidizes and forms its own protective coat of patina or rust that acts as a protective barrier to further rusting. It can be an expensive choice, but used sparingly adds a bit of urban flair.
It can be cut and welded into a variety of sizes or applications. A panel of corten steel supported between two large boulders makes an interesting pairing of materials.
Another option that can be less expensive depending on location in the yard are gabion baskets. These welded wire cages can be filled with rocks or broken concrete pieces and used for retaining walls.
The cages can be stacked to achieve the desired height, although they may need support posts, depending on the overall height of wall, soil type and slope. Different effects can be achieved by filling them with different types of rock.
Decorative edging of any color can be added to the top or face of the wall. Wood boards can be used over the top to create a seating area.
Consult a geotechnical engineer for specifications on width of bottom layer of retaining wall and drainage details. Gabion baskets can also be used to create fences or privacy wall panels.
Then there’s corrugated galvanized metal products. Here’s a material to have some fun with. Try panels supported with steel posts or stone columns for small walls. Corrugated metal culverts in a variety of sizes can be stood on end and grouped to edge a raised bed.
On another recent project with a sloped side yard, we designed a series of low stone walls to terrace the slope and topped each terrace with a galvanized steel stock tank, eliminating the need to build tall retaining walls, and allowing the homeowner to have vegetable beds that could be tended while standing up.
For more ideas, visit a salvage yard and come up with your own creative adventures in landscape design.
Pam Roy, owner of Planscapes, has been a landscape designer and horticulturist for 30 years in the Northwest. Contact her at 425-252-9469 or go to www.planscapesdesign.com for more information.